Black smoke and flames spewing from the Chevron refinery Saturday evening were caused by a malfunctioning burn-off flare, refinery officials said.

Hugh Dickey, refinery public affairs manager, said the column of smoke, which prompted dozens of calls to local fire agencies, was caused by flammable liquids entering the 50-foot flare tower, igniting at about 6:30 p.m.In turn, some of the burning liquid spilled to the ground below and burned wiring as it hit the ground. The wiring went to equipment that injects steam into the flare, which helps excess fuel and gases generated by the refinery burn more quickly. Without the steam, a thick black smoke was produced.

Property damage was minimal and no one was hurt in the mishap. The refinery's in-house fire fighting squad brought the problem under control, Dickey said.

Dickey said, that because the flare is often used as a safety valve to correct imbalances in the refinery system, it is located a distance from main refinery tanks and therefore there was little danger in the fire expanding to other refinery areas.