Eleven contract workers were injured when a fire broke out at an Indian Oil Corporation refinery at Haldia in Purba Medinipur district of West Bengal on Friday.

Four of them suffered more than 50 per cent burns and were rushed to a private hospital here, District Superintendent of Police Sukesh Jain told The Hindu on the phone.

A company official said the fire broke out near a ruptured pipeline at 1.20 p.m. Maintenance work was being done on an adjacent pipeline, and the diesel from the ruptured pipe sprayed on the workers.

The fire was brought under control in 25 minutes, Mr. Jain added.

Sources in the refinery said they were trying to ascertain how the diesel got ignited.