A charter bus carrying 26 children from a Pennsylvania school crashed on Interstate 95 in Maryland Monday morning, injuring more than two dozen people.

Axar.az reports citing TIME.

Three chaperones and a driver were also on board with the children when the bus overturned on I-95 in Havre de Grace, according to Maryland State Police (MSP). The cause of the crash had not been determined, but a car was "apparently involved in some way," said the MSP on Twitter.

The crash took place around 9:30 a.m. and blocked all southbound traffic. Fire and emergency medical services vehicles were on the scene, officials said. One adult and one child were flown in a helicopter to receive medical treatment. At least 25 in total were injured in the crash, according to the Baltimore Sun.

The MSP Office of Media Communications told TIME that public information officers were still trying to determine what happened as of 12:15 p.m, but further information wasn't yet available.