All of the company’s employees on site were accounted for; at a news conference around 5:20 p.m. — as warning sirens continued to sound in the background — Contra Costa County Fire Protection District Battalion Chief Bob Atlas said that three personnel had unspecified minor injuries.

Atlas said that the fire was “burning ferociously,” with an unknown amount of fuel remaining and declined to provide an estimate on when the fire would be put out.

Authorities said that a leak of hydrocarbons ignited the fire. There was not more information available Saturday evening about the cause of the leak or the type of fuel burning.

“Any smoke that burns, any combustible element, is going to be toxic at some point,” Atlas said at the news conference. “We’re trying to ascertain right now what exactly is in that stream of smoke.”

Crews rushed to the Martinez Refining Company at 3495 Pacheco Blvd. after the first call about 1:47 p.m., Atlas said. Fire Prevention Capt. Ted Leach said crews had difficulty locating the precise source of the flames when they got to the refinery.

Asked about the trouble pinpointing the blaze, Atlas said it was “not anything more than would normally be involved in industrial firefighting. There’s a lot of heavy steel in there, there’s a lot of materials that are in there, so getting to the scene of the fire takes a little bit of time.”

Flames were shooting some 200 feet into the air and giant black clouds were moving east with the wind, according to witnesses. Employees from the refinery were evacuated and could be seen gathered on Pacheco Boulevard, near the facility.

MNA/