(KRON) — A person is missing off the California coast after what witnesses say may have been a shark attack.

Rescue crews responded to the area of Wildcat Beach at Point Reyes National Seashore, roughly 40 miles north of San Francisco, on Sunday after receiving a missing person report, according to the Marin County Sheriff’s Office.

Friends of the missing person reported to authorities they had seen a shark and blood in the water in the area where they last spotted their friend.

At this time, officials have not confirmed a shark attack occurred.

Point Reyes NPS first reported the active search on X at noon on Oct. 1. Personnel from the National Park Service, as well as jet skis, helicopters, and fire engines from surrounding agencies, responded to the search.

The U.S. Coast Guard reportedly called off the search early Monday morning, but no additional information has been released.