MONTPELIER, Vt.-- A tour bus carrying University of Massachusetts students and others on a weekend ski trip to Quebec crashed Friday on a Vermont highway, injuring 17 people.

The bus, one of three traveling in a caravan, veered off Interstate 91 in Putney and went down an embankment, coming to rest on its side. Twenty-eight people on the bus were unhurt.

One of the injured was airlifted from the scene. Dozens of ambulances, fire trucks and emergency vehicles responded. The group was on a private ski tour that was not affiliated with the school, UMass spokesman Patrick Callahan said. Not all the passengers on the bus were UMass students, he said.

The school sent university vehicles to Vermont to transport students back to campus, Callahan said.

Seven people were taken to Brattleboro Memorial Hospital with cuts and bruises, and they were treated and released, spokeswoman Barbara Gentry said. An eighth had a neck injury and was X-rayed, but he, too, was released, she said.

Eight with minor injuries were treated and released from Springfield Hospital.

One -- a non-student -- was taken by helicopter to Dartmouth-Hitchcock Medical Center in Lebanon, N.H., but officials there wouldn't comment on the victim's injuries.

Police initially said 30 people were injured, three critically, but later revised the figure to 17 injured. "It's better than we originally anticipated," said Stephanie Dasaro, a spokeswoman for the Vermont State Police, who cited the chaotic scene for the discrepancy.

It's unclear how the crash occurred, Dasaro said. A crash reconstruction team was on the scene investigating Friday night, she said. Police didn't immediately say whether the driver would face charges.