NEW DELHI: Three workers died and six others were injured after a fire broke out and caused a blast in a food processing unit in the early hours of Saturday in the Narela Industrial Area here , the Delhi Police said.

They said they received a distress call at 3.35 am about the fire in the Shayam Kripa Foods Private Ltd that processes dry moong dal.

The fire engulfed the factory, trapping some workers in it, the official said.

Fourteen fire tenders were pressed into service and the dousing operation was still underway, a Delhi Fire Service (DFS) official said around 8.30 am.

He said nine people were rescued from inside the building and shifted to SHRC Hospital in Narela.

Three of them -- Shyam (24), Ram Singh (30) and Beerpal (42) -- were declared dead, while others were under treatment, the police officer said.

He said preliminary investigation suggest that the blaze started after a gas leak from one of the pipelines. The gas was supplied to burners used for roasting moong dal.

As the fire spread, it led to the overheating of compressor, resulting in a blast, he said.

A case is being registered under appropriate sections and investigation being taken up, he said.