A fire that forced about 850 people to evacuate from a wharf at the Port of Los Angeles is still smouldering, although officials say it is under control.

Nearly 12 hours after the blaze started, smoke is still drifting over Los Angeles Harbour.

Los Angeles fire spokeswoman Katherine Main says about 150 firefighters had the bulk of the blaze contained about two and a half hours after it broke out on Monday night, but stubborn flames underneath the docks proved hard to reach.

The fire burned about 150ft of a pier and forced the evacuation of 850 people from a warehouse and two terminals.

Ships and boats also were removed from the area.

No injuries were reported.

The Port of Los Angeles, along with its twin port in Long Beach, handles 40% of America's import trade.

The city's fire chief Ralph Terrazas said the blaze was caused by a spark from a welder's torch.

Two nearby elementary schools have been closed for the day as a precaution.

Mr Terrazas said it could take until this evening for crews to extinguish the blaze.