Two trains have collided in northern Greece with the loss of at least 29 lives and dozens of people injured, emergency services say.

Rescuers have been working through the night to try to free passengers who were on one of the trains when it crashed near the city of Larissa.

A train said to be carrying some 350 passengers hit a freight train.

Footage published on local news sites showed thick plumes of smoke rising from derailed carriages.

Around 150 firefighters and 40 ambulances were at the scene, the fire service said.

It is not yet known what caused the collision with the passenger train, which was travelling between Thessaloniki and Larissa.

"There was panic. For 10, 15 seconds it was chaos. Tumbling over, fires, cables hanging, broken windows, people screaming, people trapped," one of the train passengers, Stergios Minenis said.

"It was like an earthquake," another passenger named Angelos Tsiamouras told local media.

Another passenger named Lazos told Protothema newspaper the experience had been "very shocking".

"I wasn't hurt but I was stained with blood from other people who were hurt near me," he said.

"It was a very powerful collision," the regional governor of the Thessaly region, Kostas Agorastos, told state-run television in quotes cited by AP news agency. "This is a terrible night... It's hard to describe the scene."

Conditions for rescue workers are "very difficult", fire service spokesman Vassilis Varthakoyiannis said.

"The evacuation process is ongoing and is being carried out under very difficult conditions due to the severity of the collision between the two trains," he added.

BBC