(KRON) — A search effort resumed Wednesday for a man who went missing in the ocean after friends said they saw a shark in the water.

A 52-year-old man was swimming with two friends on Sunday, Oct. 1, when he disappeared off Wildcat Beach at Point Reyes National Seashore, according to the National Park Service. Friends of the missing man reported to authorities that a shark was seen in the area, along with blood in the water where their friend was last seen.

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

On Wednesday, National Park officials said that search and recovery efforts would continue for the day. “Six members from Marin County search and rescue along with NPS personnel are conducting a shoreline search at Wildcat Beach,” Point Reyes NPS wrote on X.

A helicopter and boat search for a missing swimmer at Point Reyes on Oct. 2, 2023. (Image courtesy Point Reyes National Park Service)

The swimmer has been missing for more than three days. Ocean water temperatures were described as “frigid” by NPS.

The United States Coast Guard suspended its search Sunday without finding the missing swimmer. Search and rescue teams with the NPS, Marin County Sheriff’s Office, Marin County Fire Department, and Stinson Beach Fire Department continued the search effort along the beach and offshore on Monday.

The swimmer was first reported missing late Sunday morning, said U.S. Coast Guard Petty Officer Hunter Schnabel. “We didn’t find the individual so there’s no way for us to confirm whether or not it was a shark attack,” Schnabel said.

Bay City News and the Associated Press contributed to this report.