A large fire erupted at the Chevron refinery around 6:40 p.m. in Richmond tonight, Monday, spewing a huge plume visible for miles and prompting authorities to issue a shelter-in-place warning.

The cloud from the fire had creeped into Concord. View photos of it here. Flames were seen shooting out of at least two towers at the refinery.

Contra Costa Health Services activated its emergency phone notification system and issued a shelter-in-place warning for Richmond, North Richmond and San Pablo. Residents were urged to remain indoors, and to close all windows and doors and seal any cracks to protect the interior from outside air. A refinery spokeswoman told KCBS that the fire erupted in the 4 crude unit and that no refinery workers had been injured.

KTVU reported that officials have issued a level-3 community warning, meaning that the fire can cause eye, skin, nose or respiratory irritation. Randy Sawyer of Contra Costa Health Services said the fire was reported about 6:40 p.m., according to Bay City News service. The refinery fire department put the time about 6:30 p.m., KTVU reported.

in Richmond and El Cerrito in response to the incident.

Officials said there was no explosion and there is a single fire and a single flare that is going off to burn off excess oil or fuel, KTVU said.

A KTVU reporter on scene said she heard alarms, a loud boom and saw a large black plume of smoke and flames. Between 200 and 300 people had stopped on nearby Interstate 580 to take photos and videos, largely with cell phones, according to KCBS.