A bus carrying children to school in southern Germany hit multiple cars and then slammed into the side of a building without braking, injuring 48 people early Tuesday, including 10 seriously, police said.

The injured were 43 children and the bus driver, as well as other adults who were aboard the bus, said Mannheim police spokesman Christoph Kunkel.

Three helicopters and 10 ambulances rushed to the scene in the town of Eberbach, about 50 kilometers (30 miles) east of Mannheim, to bring the injured to area hospitals for treatment.

The bus crashed just after 7 a.m. as it was driving around a left-hand bend in the road in Eberbach. It wasn’t immediately clear what caused the accident, but Kunkel said the driver had been able to talk with police following the crash.

A wide area around the accident scene was shut down to traffic as the incident is investigated.