MAKAHA, Hawaii - Lifeguards posted warning signs at Makaha Beach Park Friday after confirming the sighting of a 7-foot-long shark about 30-feet from the shoreline, according to city officials.

It happened just before 11 a.m.  The shark is considered aggressive because it was thrashing in the water.

City officials say the beach is not closed, but lifeguards are warning those in and out of the water.