BANGKOK, Thailand _ A homemade rocket veered out of control at a festival in provincial Thailand, killing four people and injuring 11, police said Sunday.

The accident marred the Rocket Festival in Yasothon, 280 miles northeast of Bangkok, a raucous annual celebration in which farmers launch rockets to curry favor with spirits who they believe will bring rain to their crops.

During the festivities, a 484-pound rocket lifted about 100 feet off the ground before losing control and plunging back down and exploding in a crowd of hundreds of villagers.

Police Capt. Vatanyu Rungrasamee said police were investigating why the rocket flew out of control and whether any criminal charges would be filed against the rocket's owners.