A special effects "flash pot," used by a rock band to provide a quick burst of light, injured 24 people, one critically, when it exploded Saturday on a hotel dance floor, authorities said.

The band In and Out was using the electronically detonated device for pyrotechnical effects during a show at a Holiday Inn."People said it sounded like a cannon going off - a loud bang, then shrapnel started flying," said police detective Gary Depaulo.

Seven people were admitted to hospitals, including a man listed in critical condition following surgery for leg injuries. Three of the injured were reported in serious condition.