ETNA, Maine (AP) — More than 40 vehicles crashed on a snowy stretch of Interstate 95 in Maine on Wednesday, injuring at least 17 people, police said.

The pileup in Etna, near Bangor, happened around 7:30 a.m. and involved several cars, a school bus and a tractor trailer, state police spokesman Steve McCausland said. No fatalities were immediately reported, but McCausland said some of the injuries were serious.

READ MORE: Is The Moderna Booster More Effective Than Others? Dr. Mallika Marshall Answers Your Questions

Emergency personnel climbed on top of cars to reach motorists stuck in the middle of the chaotic tangle of vehicles. McCausland said one veteran trooper described the site as a “giant pile of metal.”

Both northbound lanes on a 30-mile stretch of highway were closed for five hours, and drivers were told to take other exits to avoid the area.

One northbound lane reopened around 12:30 p.m.

Eastern Maine Medical Center had received 11 patients at its emergency department by 10 a.m., all of them in good to serious condition. St. Joseph Hospital said it was evaluating six patients from the crashes but did not release their condition.

Police said the main crash involved more than 25 vehicles, and there are a series of other wrecks leading up to the crash site. Some of the crashes involved two or three vehicles, and then other vehicles went off the road to avoid colliding with them.

READ MORE: Hunter Renfroe Named Finalist For Gold Glove Award

At a travel stop in nearby Newburgh, people involved in the crash were gathering to give statements to police, according to WZON-AM radio. Some were keeping warm in a parked school bus.

Brian Graham of Newport was driving with his daughter when he got caught up in one of the chain-reaction crashes.

“They were all pinging off of each other,” he told the radio station.

The school bus had three passengers aboard. Police said the students were “shaken up,” but not injured.

There was at least an inch of snow on the ground at the time of the crash, according to the National Weather Service. Snow was forecast to fall throughout the day with total accumulations of 5 to 9 inches.

MORE NEWS: 'It's Been Tough': Rockland, Pembroke Residents Still Without Power After Nor'easter

Copyright 2015 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.