City Ocean Safety & Lifeguard officials today posted warning signs at Waimea Bay and Waikiki due to confirmed shark sightings.

Lifeguards saw a shark, 6 feet to 8 feet long, at Waimea at about 10:15 a.m. and posted warning signs, which will remain up overnight, said Emergency Services spokesman Bryan Cheplic.

Signs were also posted in Waikiki in the Duke's Beach area after a lifeguard spotted a shark, 2 feet to 4 feet long, but the signs were removed at 3:30 p.m.