ANKARA, Turkey - A passenger train derailed in Turkey early Sunday, killing at least 9 people and injuring 24, possibly due to ice on the tracks, authorities and media reports said.

It was the nation's fifth major rail accident in less than four years.

Two cars rolled over when the train from Istanbul to the southern city of Denizli derailed near the city of Kutahya, the prime minister's office said.

It was not immediately clear how many passengers were aboard at the time of the accident. The bodies of nine passengers were recovered so far and at least 24 others were injured, NTV television said. CNN-Turk television put the injury toll at 50.

Railway authorities suspected that the train might have been derailed at a turn because of ice on the tracks, the state-run Anatolia news agency reported.

It was the nation's fifth major rail accident in less than four years.

In November 2005, a passenger train rammed into a truck carrying farm workers in southern Turkey, killing nine people and injuring 30 others. In August 2004, a passenger train ignored a stop signal and rammed into an oncoming train in northwestern Turkey, killing six people and injuring 85.

The previous month, a newly inaugurated high-speed train from Istanbul to Ankara derailed, killing 37 people. Three days later, a passenger train slammed into a minibus at a western railroad crossing, killing 15 and injuring four.