At least 36 people have died and more than 72 others have been injured after a train derailed in eastern Taiwan, officials have said.

The train, carrying around 350 people, is believed to have come off the rails in a tunnel just north of Hualien causing some carriages to hit the wall of the tunnel.

It is believed to have hit a truck that was "not parked properly" and is suspected to have slid onto the train tracks in the mountainous area, the official Central News Agency said.

Between 80 and 100 people have been evacuated from the first four carriages of the train, while carriages five to eight have "deformed" and are hard to gain access to, firefighters said.

About 70 people remain trapped in the wreckage and rescue efforts are ongoing, they added.

The crash is the island's worst rail disaster in at least four decades.

"Our train crashed into a truck," one man said in a video aired on Taiwanese television, showing pictures of the wreckage. "The truck came falling down."