MECHANIC FALLS — As many as 17 teenagers and adults were injured, some seriously, during a haunted hayride accident at the Gauntlet at Harvest Hill on Saturday night. No fatalities were reported.

Rescue units rushed to the accident scene more than one-quarter of a mile into the woods along a narrow trail that included several covered bridges.

A small jeep pulling a flatbed trailer with about 20 passengers jackknifed while going downhill and trying to round a curve. The flatbed hit a tree, throwing its passengers to the ground, Androscoggin County Sheriff Guy Desjardins said.

The two most seriously injured riders were airlifted by helicopter; others were taken by ambulance to hospitals in Lewiston and Portland.

Victims suffered injuries to backs necks and limbs, including fractures.

“It was quite a job just trying to negotiate the ambulances inside that area,” Desjardins said.

The accident occurred during the part of the ride known as the haunted Frankenstein’s house, he said. That’s where the jeep typically slows, but the ride went awry. The jeep went one way and the trailer went the other way, then struck a tree.

The driver of the jeep apparently suffered a neck injury, Desjardins said.

Seventeen patients, including 12 brought by ambulance, were seen at Central Maine Medical Center in Lewiston, according to Chuck Gill, vice president for public affairs.

One victim was in “very critical condition,” he said, and some of the few to be admitted needed surgery.