By Janusz Chmielewski
SZCZEKOCINY, Poland, March 4 (Reuters) - The death toll from Poland's worst rail crash in two decades rose to 16 on Sunday as rescue workers searched the mangled wreckage of two express trains that collided head-on at high speed.
President Bronislaw Komorowski said he would announce a period of national mourning for those killed when the trains collided late on Saturday near the town of Szczekociny in southern Poland. Nearly 60 of the estimated 350 passangers on board were injured.
The battered locomotive of one of the trains had been forced upwards in the crash, most of the carriages had derailed and some were lying on their sides.
Officials said they could not rule out finding more bodies as heavy machinery began the task of pulling apart the wreckage.
"After the rescue operation is over, I will take a decision about national mourning because it took place at the border of three provinces and the victims were from all over Poland," Komorowski, who visited the scene on Sunday, said.
"The scope of this disaster is sufficiently large to warrant national mourning," he said.
Komorowski also visited some of the survivors in hospital. The injured passengers were taken to several hospitals in the region by helicopter and ambulance.
More than 350 firefighters and other rescue workers struggled overnight to extract the victims from the twisted wreckage at a remote field crossed only by a pair of rail tracks.
"This certainly is the most tragic train catastrophe in our history in many, many years," said Prime Minister Donald Tusk, who arrived at the site of the crash with several other government officials early on Sunday.
"There was no braking, only the crash, and the lights went out, people were screaming," passenger Dariusz Wisniewski told a local television station. "When we got out we saw bodies and wounded all over, as well as the twisted wreckage. I had never seen anything like it."
Tusk said it was too early to speculate about the cause of the collision, but said human error could not be ruled out. Transportation Minister Slawomir Nowak said one of the trains, bound for Krakow, was on the wrong side of the track.
Authorities were opening an investigation.
The fate of the two drivers was not immediately known. Among the passangers were several Ukrainians along with French and Spanish citizens.
One of the trains had been going from Warsaw to Krakow and the other from the city of Przemysl to the capital.
The wreckage on one of Poland's most heavily used train routes was causing delays of up to three hours on Sunday.
In 1990, 16 people were killed in a train crash in Warsaw. (Additional reporting by Piotr Pilat and Rob Strybel; Writing by Chris Borowski; Editing by Janet Lawrence)