A cannon blast at a parade in Utah sparked an explosion, sending three children to the hospital.

Police say the accident occurred when a Civil War reenactment group fired a cannon Saturday at the start of the Summerfest Parade in Orem, about 45 miles south of Salt Lake City.

Investigators say sparks from the cannon landed in a large pouch containing additional charges for the cannon and the pouch then exploded.

Witnesses told KUTV-TV that two of the three children appeared to be engulfed in flames.

Police say all three children were treated at the scene and taken by ambulance to a local hospital in stable condition.

The children were part of the Civil War reenactment group and were participating in the parade.

The explosion is under investigation.