City Ocean Safety and Lifeguard Services officials are keeping shark warning signs posted overnight at Makaha Beach and will reassess the situation tomorrow morning.

Warning signs advising surfers and swimmers to stay out of the water were posted today after an 8- to 10-foot shark was spotted shortly after 10 a.m. about two yards offshore, said Bryan Cheplic of the Honolulu Emergency Services Department.

The water is dirty — full of debris and runoff from the recent heavy rainfall — and the threat of leptospirosis exists, which is another reason lifeguards are advising people to stay on shore, Cheplic said.