At least five workers were killed and scores more feared trapped on Friday after a massive mound of earth caved in at a coal mine in eastern India.

The collapse buried at least 23 miners and dozens of vehicles under the debris as hundreds of emergency workers battled overnight to rescue the men at the Lalmatia open cast mine in Jharkhand state's Godda district.

"We have retrieved five dead bodies and another 23 are said to be trapped under the debris," Harilal Chauhan, Godda police chief, told AFP.

Chauhan said the exact number of workers trapped under tons of earth was not yet known, with some unconfirmed media reports putting the number at 50.

Authorities dispatched more than 200 rescue workers from the federal National Disaster Management Authority to the site to help with rescue work.

The mine is operated by the government-owned Eastern Coalfields Limited, whose top official Niladri Roy told AFP that more than 250 meters of mine collapsed as the workers headed towards the exit gate around 7:30pm local time.

There was no immediate explanation for the collapse.

All the miners are employed by a private contractor and work round-the-clock.

In a separate incident on Thursday four miners were injured at a government-run coal mine in Jharkhand's Dhanbad district.

A mine official said the workers were hit after the roof off the Putki Balihari coal mine collapsed partially. Two of the injured were in a critical condition.

Jharkhand is one of the richest mineral zones in India, and accounts for around 29 percent of the country's coal deposits. However it is also one of India's poorest areas and epicentre of a Maoist insurgency.

Source: AFP