BAR HARBOR – A knife fight at the town ball field Thursday night left one juvenile boy in police custody and another airlifted to Eastern Maine Medical Center in Bangor.

The victim, a 17-year-old from Bar Harbor, apparently was stabbed about 9 p.m. above the heart, on the side of his head and on his right shoulder, according to police. He was taken to the hospital by LifeFlight emergency helicopter.

The assailant, a 16-year-old from Mount Desert, also had been wounded on his right wrist and was receiving medical care before being transported to the Mountainview juvenile correctional facility in Charleston. The assailant told officers that the victim wounded him.

The knives involved were multiuse tools, similar to Leatherman knives, and had blades that were 2 to 3 inches long, according to police. The cause of the fight was unknown, an officer said. The police would not release the names of the juveniles involved.

Sgt. Allen Smith of the Bar Harbor Police Department said that he had received a noise complaint about a gathering at the ball field, and was monitoring the group of eight to 10 young people at the scene when he saw the fight begin.

“I saw a squabble in the parking lot,” Smith said Thursday night. “I headed right in and by that time he had already been stabbed.”

When Smith approached the victim, he was conscious but bleeding “quite a bit.” The officer said he then began to sort out the situation, called an ambulance and arrested and handcuffed the alleged assailant, who was charged with aggravated assault.

The sergeant said that the victim’s injuries were not believed to be life-threatening.

“We have recently been getting more complaints on noise and large groups [at the ball field],” Smith said. “We’ll probably be clamping down on kids hanging out down there.”

Smith said that girls and legal adults also were involved in the gathering at the ball field.