Alang (Gujarat), Aug 4 - Six labourers were burnt to death at Asia's biggest ship-breaking yard in this Gujarat town when an old vessel they were working in caught fire Tuesday, police said.

The six labourers were carrying out steel cutting operations inside the vessel, said to be an oil tanker, berthed on Plot number 24 of the ship-breaking yard at Alang in Bhavnagar district, about 240 km from here.

The immediate cause of the fire was not known, police said, adding that the Gujarat government had ordered an inquiry.

The fire broke out in one of the chambers of the vessel and spread quickly. The labourers working outside the ship raised an alarm and fire brigade personnel rushed to the spot. After nearly half an hour, the fire was brought under control.

A rescue operation was launched for the six labourers, but only their charred bodies could be recovered, police said.

The incident once again underlines the need for improving safety conditions at the ship-breaking yard, which has witnessed several cases of fire, police added.