Two passenger trains collided in Iran’s north-central Semnan province early today, killing at least 31 people and injuring dozens.

Citing Iranian media agencies, Reuters reported that the number of fatalities and casualties are expected to rise.

“At least 15 people were killed and over 20 others have been injured in the crash,” the semi-official Mehr news agency quoted the head of Iran’s Red Crescent Ali Asghar Ahmadi as saying.

Reports gave no details on the number of passengers in the trains. But Fars, another Iranian news agency, said 100 passengers had been rescued.

State television showed footage of four derailed carriages, with two of them on fire. A spokesman for Iran’s Red Crescent, Mostafa Mortazavi, told Fars that firefighters were trying to control the blaze.

“The accident happened when a passenger train in motion crashed to another one that had stopped at the station,” it said.

The cause of the collision was under investigation, it said, adding that rescue teams have been dispatched to the site of accident.