MEXICO CITY -- Mexico City authorities say they have arrested a police officer and another man in the abduction and killing of 12 young people who were taken in May from a bar near the U.S. Embassy.

Mexico City Attorney General Rodolfo Rios says the two suspects helped kidnap the group, whose decomposing bodies were found last month buried in a ranch near the capital.

Rios says the police officer worked in the Zona Rosa, a touristy area of bars and restaurants where the 12 were kidnapped.

He said Thursday the latest arrests bring to 15 the number of suspects in custody.

Prosecutors have said they believe the killings were in revenge for the slaying of a drug dealer in the trendy Condesa neighborhood.

Earlier on HuffPost:

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  • Local self-defense squads watch as Mexican army soldiers enter the town of La Ruana, Michoacan, Mexico, Monday, May 20, 2013. Residents of western Mexico towns who endured months besieged by a drug cartel are cheering the arrival of hundreds of Mexican army troops. Hundreds of people in the state of Michoacan have taken up arms to defend their villages against drug gangs, a vigilante movement born of frustration at extortion, killings and kidnappings in a region wracked by violence. (AP Photo/Marco Ugarte)

  • Residents greet Mexican army soldiers as they enter the town of La Ruana, Michoacan, Mexico, Monday, May 20, 2013. (AP Photo/Marco Ugarte)

  • Mexican army soldiers enter the town of La Ruana, Michoacan, Mexico, Monday, May 20, 2013. (AP Photo/Marco Ugarte)

  • Mexican army soldiers enter the town of La Ruana, Michoacan, Mexico, Monday, May 20, 2013. (AP Photo/Marco Ugarte)

  • Mexican army soldiers enter the town of La Ruana, Michoacan, Mexico, Monday, May 20, 2013. (AP Photo/Marco Ugarte)

  • A group of armed guards stand with their weapons at the entrance of the town of La Ruana, Michoacan, Mexico, Monday, May 20 2013. (AP Photo/Marco Ugarte)