WESTMINSTER, Colo. — Authorities searched fields and along highways in suburban Denver on Monday for signs of a 10-year-old girl who has been missing since leaving for school on Friday and whose backpack may have been found miles away.

The effort to find fifth-grader Jessica Ridgeway also focused on the area around the home in Westminster where she lives with her mother, and a neighborhood 6 miles to the north where the backpack believed to belong to her was found Sunday.

Ridgeway was last seen Friday walking to a park where she meets classmates before school. A police flier with her photo was posted on the front door of her two-story home that was decorated for Halloween.

The FBI was assisting the investigation, and investigators have been in contact with relatives in Independence, Mo.

Jessica's great-grandmother Dana Moss told KSHB-TV that she consented to a search of her house because "we'd do anything in the world to get her back."

"Safely, alive, however we can have her back," she said.

The Associated Press couldn't immediately reach Moss.

In Westminster, police stationed officers at elementary schools to assist children, though they said there was no indication that other children were in danger.

"We have no reason to believe there is a person going around abducting children," police spokesman Trevor Materasso said.

However, police in the nearby suburb of Arvada said they were investigating whether the disappearance of Jessica was related to two recent child enticement cases that involved a man who tried to lure two boys about the same age as Jessica into a car.

No suspects were identified in those incidents, which took place about 6 miles south of Jessica's home.

"Our detective is working to see if they're related," Arvada police spokeswoman Jill McGranahan said.

A resident in a neighborhood in Superior, a town along U.S. Highway 36 linking Boulder and Denver, reported finding the backpack on a sidewalk.

Police declined comment about its contents. Materasso said it was sent to the state crime lab for analysis that involved DNA samples from the family.

Authorities got a late start searching for Jessica because her mother works nights and slept through a call Friday from school officials after Jessica didn't arrive for classes.

People in the area have been moved to help in the search.

More than 800 volunteers turned out for Saturday's search, and at least 300 leads have been called in to a tip line.

So many police fliers have been posted on fences and windshields around the city that authorities were having trouble keeping up with demand for the material.

____

P. Solomon Banda reported from Denver.

Loading Slideshow...
  • Missing School Girl

    This image provided by the Westminster Colorado Police Department shows 10-year-old Jessica Ridgeway. Police in Westminster are looking for a 10-year-old girl who was last seen walking to school. Jessica Ridgeway normally meets a friend at a park on her way to Witt Elementary School, but she didn’t make it to the park or school Friday Oct. 5, 2012. An Amber Alert has been issued. (AP Photo/Westminster Colorado Police Department)

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • 150105_10151341575584305_1291829664_n

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    Via <a href="http://www.facebook.com/media/set/?set=a.10151340500824305.521112.141296864304&type=1">Westminster PD's Facebook page</a>.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Department released new photos of missing 10-year-old Jessica Ridgeway. The picture is dated June 25th, 2011.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is dated July 6, 2006.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo of Jessica is dated July 13, 2006.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Jessica Ridgeway

    The Westminster Police Dept. provided <a href="http://www.facebook.com/pages/Westminster-PD/141296864304">new photos of missing 10-year-old Jessica Ridgeway on their Facebook page</a> Tuesday. Jessica has been missing since Friday Oct. 5th. This photo is undated.

  • Arvada Police spokeswoman Jill McGranahan, left, and Westminster Police spokesman Trevor Materasso, right, address the media regarding a body found lat Wednesday in Parttridge Park in Arvada during a press conference at the Westminister Police Department Thursday, Oct. 11, 2012 in Westminister, Colo. The search missing 10-year-old Jessica Ridgeway will continue, police said Thursday. (AP Photo/Barry Gutierrez)

  • Missing School Girl

    A police officer walks through a field of tall grass searching for ten-year-old Jessica Ridgeway near her home in Westminster, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Missing School Girl

    Denis McLaughlin leads his search and rescue dog through a field of tall grass searching for ten-year-old Jessica Ridgeway near her home in Westminster, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Missing School Girl

    Members of a search and rescue team use a dog while searching for ten-year-old Jessica Ridgeway near her home in Westminster, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Missing School Girl

    A member of a search and rescue team leads his dog through a field of tall grass searching for ten-year-old Jessica Ridgeway near her home in Westminster, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Missing School Girl

    A Westminster police officer sits in her partrol car at the home of ten-year-old Jessica Ridgeway in Westminster, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Missing School Girl

    A missing poster for ten-year-old Jessica Ridgeway is seen in Broomfield, Colo., on Monday, Oct. 8, 2012. The youngster has been missing since she left her home Friday morning on her way to school. (AP Photo/Ed Andrieski)

  • Arvada Police spokeswoman Jill McGranahan, left, and Westminster Police spokesman Trevor Materasso, right, address the media regarding a body found lat Wednesday in Parttridge Park in Arvada during a press conference at the Westminister Police Department Thursday, Oct. 11, 2012 in Westminister, Colo. The search missing 10-year-old Jessica Ridgeway will continue, police said Thursday. (AP Photo/Barry Gutierrez)

  • Police search near an area where a body was found Wednesday in Parttridge Park, in Arvada, Colo., during the ongoing search for missing 10-year-old Jessica Ridgeway on Thursday, Oct. 11, 2012. Police are not saying whether the body found is linked to the missing girl case and noted Thursday that officers are still searching for Ridgeway, who disappeared Oct. 5. (AP Photo/Barry Gutierrez)

  • Police search near an area where a body was found Wednesday in Parttridge Park, in Arvada, Colo., during the ongoing search for missing 10-year-old Jessica Ridgeway on Thursday, Oct. 11, 2012. Police are not saying whether the body found is linked to the missing girl case and noted Thursday that officers are still searching for Ridgeway, who disappeared Oct. 5. (AP Photo/Barry Gutierrez)

  • Police search near an area where a body was found Wednesday in Parttridge Park, in Arvada, Colo., during the ongoing search for missing 10-year-old Jessica Ridgeway on Thursday, Oct. 11, 2012. Police are not saying whether the body found is linked to the missing girl case and noted Thursday that officers are still searching for Ridgeway, who disappeared Oct. 5. (AP Photo/Barry Gutierrez)

  • Police search near an area where a body was found Wednesday in Parttridge Park, in Arvada, Colo., during the ongoing search for missing 10-year-old Jessica Ridgeway on Thursday, Oct. 11, 2012. Police are not saying whether the body found is linked to the missing girl case and noted Thursday that officers are still searching for Ridgeway, who disappeared Oct. 5. (AP Photo/Barry Gutierrez)

  • Police search near the 9800 block of Alkire St. on the west side of Stanley Lake in Arvada, Colo., during the ongoing search for missing 10-year-old Jessica Ridgeway on Thursday, Oct. 11, 2012. Police are not saying whether a body found in Pattridge Park on Wednesday is linked to the missing girl case and noted Thursday that officers are still searching for Ridgeway, who disappeared Oct. 5. (AP Photo/Barry Gutierrez)