A head-on collision between a passenger train and a freight train in Greece has left 36 people dead.

The accident happened late Tuesday near the town of Tempe, about 200 kilometers north of the capital Athens.

Local fire department officials say 66 others are being treated at hospitals.

Local media have quoted railway officials as saying the passenger train was heading to Thessaloniki in the north with about 350 people on board.

Video taken the morning after the collision shows train cars flung off the tracks with shattered windows and twisted doors.

Workers were shown trying to remove the wreckage using multiple cranes.

The Greek government announced a three-day period of national mourning from Wednesday.

It will investigate the cause of the accident in which the two trains traveled several kilometers on the same track from opposite directions before they collided.