California officials are searching for a car that drove off a cliff in California on Monday, as well as possible passengers inside the vehicle.

The SUV was spotted driving off a cliff at Gray Whale Cove State Beach, about 18 miles south of San Francisco, by a witness.

A six-hour search for bodies was suspended Monday, U.S. Coast Guard Petty Officer Taylor Bacon said, and remained halted as of Thursday afternoon due to a lack of visibility and dangerous water conditions in the area.

"The risk outweighed the potential of finding somebody," Bacon told USA TODAY. "This is a unique situation and we're working with partner agencies to help find the vehicle."

The California Highway Patrol, the U.S. Coast Guard, the San Mateo County Sheriff's Office and Cal Fire are all searching for the car and possible passengers.

The witness spotting was further corroborated by footage from a dashboard camera, some car debris and tire marks on the sand surrounding the cliff's edge.

CHP officer Bert Diaz said that investigators have been looking for missing persons and missing vehicle reports, but haven't found anything.

“We don’t know if it was a criminal act," Diaz said. "We don’t know if it was intentional or if it was an accident."

Crews will continue the search when conditions improve.

Contributing: Associated Press