At least three people were killed when a school bus carrying high school students plunged off an interstate overpass in Alabama Monday.
Police in Huntsville, Alabama said three girls were killed in the accident.
Police spokesmen say the bus hit a guard rail and fell about nine meters before overturning on a road below.
The chief of police in Huntsville says officers are looking for a car that may have come close to or hit the bus, causing it to veer off the overpass.
The bus was carrying 34 students. Eleven youths were treated on the scene and the others were taken to local hospitals, some with severe injuries.
Some information for this report was provided by AP and Reuters.