Santa Barbara County health officials Friday closed Summerland Beach after large volumes of oil washed up on the sand.
Health officials say they first issued a health warning about 1:30 p.m. after oil was spotted in the water and on the sand, then closed the beach a few hours later. They said there were also reports of strong petroleum odor in the area.
The U.S. Coast Guard responded to the area about 3 p.m. in response to a call about a 300-yard substance near the beach.
County health officials said they don't know where the oil is coming from, but they don't believe it is related to the Refugio
Summerland Beach is adjacent to Santa Barbara County's Lookout Park, which is about six miles south of Santa Barbara.
"At this time, it is not clear when the beach will reopen to visitors," the department said in a statement. "The beach closure may continue throughout the weekend."