A fire broke out Monday in Iraq's largest oil refinery in the northern town of Beiji, and 10 people suffered burns injuries, police and an engineer at the refinery said.

The fire broke out at about 2 p.m. in a production unit that had recently undergone maintenance work, the engineer and the police officer said. Both spoke on condition of anonymity because they were not authorized to release information.

Engineers said maintenance work had been carried out on units producing liquid gas and petrol, and that the blaze was believed to have been caused by a technical problem as one unit began operating again.

Firefighters were on the scene, police said.

Beiji, 155 miles north of Baghdad, serves as a key transfer point for crude oil being exported out of Iraq.