A school bus and 18-wheeler collided on Highway 45 at Porterville-Sucarnochee Road in Kemper County late Monday afternoon.
The bus driver and some children were taken to the hospital by ambulance and private vehicles.
"The tanker truck was southbound. The school bus was eastbound. Information indicates seven people on the bus were transported to hospitals in Meridian. The cause is under investigation," said Sgt. Ronnie Carter, spokesman for Troop H of the Mississippi Highway Patrol.
MHP and Kemper County authorities responded to the scene. About 40 people were on the bus. The truck driver was not injured.