Rescuers work at the site where a school bus collided with a dump truck in Paramus, New Jersey, the United States, on May 17, 2018. A student and a teacher were killed and dozens others were injured when a school bus full of fifth-graders collided with a dump truck on a New Jersey highway Thursday morning, Governor Phil Murphy said. (Xinhua/Li Muzi)

WASHINGTON, May 17 (Xinhua) -- A student and a teacher were killed and dozens others were injured when a school bus full of fifth-graders collided with a dump truck on a New Jersey highway Thursday morning, Governor Phil Murphy said.

The students, fifth graders at East Brook Middle School in Paramus, New Jersey, were on their way to a field trip when the collision occurred, Murphy told a news conference from the school.

There were seven adults, including the driver, and 38 students on board the bus, according to Murphy. Apart from the two died, all the others were injured and taken to the hospital for treatment.

Some of those injured are in critical condition and undergoing surgery, the governor said.

The crash happened just before 10:30 a.m. on I-80 West in Mount Olive Township, with the bus ending up on its side in the grass median.

Mount Olive Mayor Rob Greenbaum who was observing the rescue efforts at the scene said that the bus was "mangled" with its chassis detached from the rest of the vehicle.

"It's a horrific scene," he said. Route 80 is closed in both directions in the area, police said.