Oahu emergency services is warning people to be aware of an aggressive 13-foot tiger shark about 300 yards out in Yokohama Bay.

EMS public information officer Shayne Enright said in a new release that the shark came up on two divers about 2:20 p.m. today and hit one of their bags. They tried to fire a bang stick but the device misfired. So one of the guys climbed a cliff and notified lifeguards who used a jet ski to rescue the other diver. 

Warning signs are posted and lifeguards are sticking around later than usual to watch the area. More information including the latest details is available at the ocean safety website.