Town of Hempstead lifeguards spotted another shark at Lido Beach Saturday, officials say.

They say a lifeguard noticed a large, dark fin emerging from the water and seemingly going after prey.

Officials say the lifeguard and some swimmers noticed a large splash, and the swimmers ran out of the water.

They say the lifeguards then prompted everyone to get out of the water. Officials say that shark patrol had just finished checking the water, but went to investigate.

Lifeguards say there were a lot of rays being in the water, which are considered prey for sharks.

Nassau County police say they've also spotted a shark, and all swimming is prohibited at Town of Hempstead ocean beaches from Civic Beach to Lido West beach until further notice.