At least 32 people were killed and another 85 injured after a collision between two trains caused a derailment near the Greek city of Larissa late Tuesday night, authorities said.
A fire services spokesman confirmed that multiple carriages skipped the tracks just before midnight after the trains -- one for freight and the other carrying 350 passengers -- collided about halfway along the route between Athens and Thessaloniki.
"Thirty-two people have been found dead," spokesman Vassilis Vathrakogiannis told reporters, adding that efforts to rescue people still trapped were ongoing.
"Of the 85 people injured, 53 people remain in hospital."
An explanation for why the two trains collided has not yet been furnished.
Greek media are calling the crash the "worst train accident that Greece has ever known".
The passenger train had been travelling from the capital Athens to second city Thessaloniki in the north, while the freight train was heading in the opposite direction.
About 150 firefighters and 40 ambulances were mobilised for the response, according to Greek emergency services. Cranes and mechanical personnel were also deployed to try to remove debris and right overturned vehicles.
"I've never seen anything like this in my entire life. It's tragic. Five hours later, we are finding bodies," said an exhausted rescuer emerging from the wreckage where he and his team were working.
One train carriage was completely crushed, making the rescuers' work particularly difficult, while smoke and flames emerged from other cars.
"The majority of passengers have been taken to safety," spokesman Vathrakogiannis said.
"The operation to free trapped people is underway and is taking place in difficult conditions, due to the seriousness of the collision between the two trains."
According to public television station ERT, one of the train cars caught fire after the collision and several people were trapped inside.
The mayor of the nearby town of Tempi, Yorgos Manolis, told ERT many students had been on board the train, returning to Thessaloniki after a long holiday weekend.
'Stained with blood'
One passenger named Lazos told the newspaper Protothema that the experience had been "very shocking".
"I wasn't hurt, but I was stained with blood from other people who were injured near me," he said.
On the local media site Onlarissa, a young woman said through tears that the train "was stopped for a few minutes when we heard a deafening noise".
Another shaken passenger told Skai television that "the windows suddenly exploded. People were screaming and were afraid".
"Fortunately, we were able to open the doors and escape fairly quickly. In other wagons, they did not manage to get out, and one wagon even caught fire," he added.
An emergency government meeting was organised after the crash, and Greek health minister Thanos Plevris went to the scene while interior minister Takis Theodorikakos supervised the response from a crisis management centre.
The two hospitals near Larissa have been requisitioned to accommodate the many injured, according to the fire services, while military hospitals in Thessaloniki and Athens are also "on alert" in case they are needed.