A school bus taking children on a field trip to a New Jersey historic site collided with a dump truck Thursday, ripping the bus apart, knocking it on its side and injuring multiple people.

The front end of the school bus appeared to be ripped off as it sat on the median of Interstate 80 in Mount Olive. It was also sheared off its undercarriage and a piece of the front end of the bus with the steering wheel visible was lying on top of the guardrail separating the highway from the median.

A red dump truck with a mangled front end was parked along the highway nearby, about 50 miles (80 kilometers) west of New York. The truck was registered to Mendez Trucking, of Belleville, and had "In God, We Trust" emblazoned on the back of it.

"It's a horrific scene," Mount Olive Mayor Rob Greenbaum told The Record.

"Our hearts are broken by today's tragedy," Democratic New Jersey Gov. Phil Murphy said in a tweet.

Paramus Public Schools said that the bus was taking students from East Brook Middle School to Waterloo Village, which is about five miles from the crash scene. Students on two other buses on the field trip returned to the school Thursday morning and were reunited with their parents, said Paramus police Commissioner Holly Tedesco.

A sign outside of the school, about 50 miles (80 kilometers) from the crash site, informed people to go to the auditorium for updates on the accident and the school was offering crisis counselling.

State police said that an unknown number of children were on the bus, but they didn't know how serious the injuries are. Hackettstown Police Sgt. Darren Tynan told The Record that multiple people were taken to a hospital.

Seventh-grader Alejandro Garcia told The Record that students were told to return to homeroom on Thursday morning. As his classmates started searching online to see what had happened, they realised there had been an accident.

"People who I'm close friends with, who have brothers and sisters on that bus, started crying, and everybody just started sympathising," Garcia said. "It was just a time of need for everyone."

At least two canine units were searching the woods along the roadside Thursday afternoon, but it wasn't clear why.

Mendez Trucking has 33 drivers and 33 trucks, according to the Federal Motor Carrier Safety Administration. A message left with the company wasn't immediately returned. Its trucks have been in seven crashes in the last two years, none of them fatal, according to FMCSA.

Mendez was fined $22,850 in 2016 for violating regulations on inspections, repairs and maintenance and post-crash drug and alcohol testing, according to the FMCSA.

Mendez has a higher than average vehicle out-of-service rate, which means inspections found violations which had to be corrected before the vehicle could be returned to service. Mendez's rate was 37.9 percent, according to FMCSA. The national average is 20.7.

"From what I saw, the red truck was destroyed, but the bus appeared worse," Manuel Absalon, a tourist from Mexico driving by the crash site, told WNBC-TV. "It looked like it was broken in half."

Morristown Medical Center spokeswoman Elaine Andrecovich said they have received some people from the accident, but she did not have a number available and could not say how many were children.

About 10 victims were taken to St. Clare's Dover Hospital and St. Clare's Denville Hospital, according to Communications Director Patty Montgomery. She said they were being evaluated and treated, but she did not have ages or conditions.

St. Joseph's Health public relations manager Pam Garretson said two children were being evaluated in the emergency room. She did not know their conditions or ages.

Waterloo Village is a historic site depicting a Lenape Indian community and once-thriving port along the Morris Canal in northwestern New Jersey. It features several historic homes, a blacksmith shop, general store and more. It's a popular spot for school trips. (AP)

Update news