BIOCE, Serbia-Montenegro - The driver of a train that plunged into a 330-foot-deep ravine in Montenegro may have failed to lock the brakes after he left his seat to make a repair, officials said Tuesday. At least 44 people were killed and 198 injured.

Authorities on Tuesday placed the injured train driver in police custody in the hospital, saying he was suspected of negligence.

The train was emerging from a tunnel above the Moraca river when it derailed on Monday near Bioce, a village about nine miles northeast of Montenegro's capital Podgorica, police said.

The driver apparently stopped before the tunnel to make a repair, and failed to lock the brakes, a railway official told The Associated Press. That set the train in motion without him in the driver's seat, the official said. He spoke on condition of anonymity because he was not authorized to give details to the media.

A railway authorities' statement said the driver failed to "comply with the official proceedings during (the train's) standstill" and that "prompted the train to set itself in motion."

At least 250 passengers, many of them children returning from a ski trip, were believed to have been on the train when it crashed, one of the deadliest European train accidents in 25 years.

Initial reports had indicated the train's brakes may have failed.

Health Minister Miodrag Pavicevic put the death toll at 44. But rescuers said they had found one more body crushed inside the twisted wreckage of the train, and that death had not been added to the official count.

Of 198 people injured, the minister said 32 children remained hospitalized.

Rescuers searched the wreckage of the four carriages Tuesday. They said not all passengers had been accounted for.

An unidentified teenage survivor, hospitalized in Podgorica, told state TV he saw the train driver "checking wires and electricity switches in the last car."

"The man said, 'We are doomed,' and the train sped away into the tunnel before it derailed," the teenager said.

Grieving relatives lined up outside a tent at the Podgorica hospital morgue Tuesday to identify the dead and take their bodies home.

"I lost my whole life in this tragedy," sobbed Radomir Cobarkapa, 50. His wife and son were killed in the crash, and two of his other children were injured.

Tarzan Milosevic, the mayor of Bijelo Polje, came to claim the bodies of 24 people from his northeastern town. "There are no words to describe this," he said through tears.

Transport Minister Andrija Lompar and the head of Montenegro railways, Ranko Medenica, resigned because of the accident.

Serbia-Montenegro President Svetozar Marovic described the crash as a "great tragedy," and a three-day mourning period was announced.