Lifeguards have ordered everybody out of the water in Huntington Beach after a shark bumped a surfer.

The surfer told authorities a 5-to-8-foot-long shark bumped the underside of his board Friday morning as he sat waiting for a wave.

The surfer paddled about 30 yards back to shore and alerted lifeguards.

Authorities say the bump qualifies as aggressive shark behavior. They've closed the waters along a 2-mile stretch of beach until Saturday morning. However, beachgoers can still use the sand.