Multiple people were killed when a charter bus collided with a passenger vehicle on a Pennsylvania highway, officials said.

The crash happened shortly before midnight Sunday on southbound Interstate 81 near Lower Paxton Township in Dauphin County, the Pennsylvania State Police said.

The bus, which was carrying 45-50 passengers, "flipped on its side and came to final rest on the right berm," state police said.

"Multiple passengers on the bus are deceased. Multiple people have been transported to Hershey Medical center for varying injuries," police added.

Police are withholding the names of those killed until the next of kin are notified, officials said.

Lower Paxton Township is about 10 miles east of Harrisburg.