Brake failure may have caused a passenger train to plunge into a ravine outside Montenegro's capital, killing at least 44 people and injuring 198, officials said Tuesday.

Rescuers were scouring the wreckage for survivors and not all passengers aboard had been accounted for by Tuesday afternoon. It was one of the deadliest European train accidents in 25 years.

At least 250 passengers, many of them children returning from a ski trip, were believed to be aboard.

The train derailed Monday near Bioce, a village about nine miles northeast of Podgorica, as it emerged from a tunnel above the Moraca River. It plummeted into a 330-foot ravine.

Interior Minister Jusuf Kalamperovic said initial reports indicated brake failure may have been the cause. The injured train driver was being held under police custody in the hospital on suspicion of negligence.

Health Minister Miodrag Pavicevic said at least 44 people died and 198 were injured. The death toll could soon rise to 45 because rescuers said they had discovered one more person crushed in the wreckage who had not yet been counted in the official tally.

There were 90 children among the injured, said Miodrag Djurovic, the head of the main Podgorica hospital.

Serbia-Montenegro President Svetozar Marovic said the accident was a "great tragedy" for Montenegro. A three-day mourning period was declared for the victims.

A 17-year-old passenger gave birth to a boy at the hospital Tuesday after her injuries induced premature labor.

Overnight, darkness in the densely forested area hampered rescue efforts. Victims had cried for help from the deep ravine and emergency workers removed bodies tangled in the four smashed train cars and strewn around nearby patches of woodland.

"The train simply went wild, out of control," a man who survived said as blood poured down his forehead. "I was fine because I was in a back compartment, those in the front got the worst of it."

Grieving relatives lined up outside an improvised tent at the Podgorica hospital morgue to identify the dead and take the bodies home.

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

Tarzan Milosevic, mayor of the northeastern town of Bijelo Polje, came to claim the bodies of 20 of his townspeople who were killed. The train was en route from Bijelo Polje to the Montenegrin coastal city of Bar when it derailed.

"There are no words to describe this," he said through tears.

Montenegrin Prime Minister Milo Djukanovic visited the Podgorica hospital where many of the injured were taken and said emergency crews had "reacted as well as could be expected in such a harsh and inaccessible terrain."

"We did all we could, but in many cases that was not enough to save those tragically killed," he said.

Transport Minister Andrija Lompar resigned because of the accident, Deputy Prime Minister Miroslav Ivanisevic said. The head of Montenegro railways also resigned.

Other deadly train accidents in Europe in recent decades included the June 1998 derailment of a high-speed train traveling from Munich to Hamburg, which killed 96 people. A crash in a dead-end tunnel at Moorgate Underground station in central London killed 43 in February 1975.