A local passenger train ran into the back of an long-distance train Monday near Budapest, killing four people and injuring 26.

National Rescue Service spokesman Pal Gyorfi said two women and one man died at the scene and at least eight other passengers were seriously hurt, some with life-threatening injuries.

Hungarian state news agency MTI reported that another victim died after being taken to a Budapest hospital.

Gyorfi said it was possible more casualties would be found in the wreckage.

The accident happened around 10:20 a.m. (0820 GMT) near the train station in the town of Monorierdo, when a local passenger train ran into the back of a long-distance train coming from the eastern city of Nyiregyhaza, Hungarian State Railways, or MAV, said in a statement.

Both trains were heading toward Budapest, Hungary’s capital, about 40 kilometers (25 miles) northwest of Monorierdo.

A MAV spokesman at the scene of the accident said the long-distance InterCity train slowed down or may have come to a halt before the Monorierdo station due to a malfunctioning signal on the tracks.

“We don’t know why the local train caught up with the one ahead of it, as security precautions should have prevented the accident from happening,” MAV spokesman Tibor Sigulinszki said in a telephone interview. “This is what we are investigating now.”