An Air Force utility helicopter on a routine training mission took ground fire over Virginia on Monday, forcing an emergency landing and leading to the injury of a crew member, according to military and federal officials.

The UH-1N Iroquois helicopter, assigned to Joint Base Andrews in Maryland, was soaring east of Shenandoah National Park around 1,000 feet when the incident occurred, an Air Force spokesperson said Wednesday.

The gunfire damaged the aircraft, necessitating an emergency landing at nearby Manassas Regional Airport at 12:43 p.m., the spokesperson said.

About 20 minutes earlier, the tower at the airport alerted airport officials that the aircraft was approaching with an “onboard emergency,” airport operations officer Richard Allabaugh told The Washington Post. The reports indicated that a member of the crew was bleeding from a hand wound, Allabaugh said.

The crew member was treated for a “nonthreatening injury” at a hospital and was released, said a spokesperson for the FBI’s field office in Washington.

It is unclear whether the crew member was struck by a bullet, hit by debris or injured in the commotion during the incident, which was first reported by McClatchy. It was also not known who fired at the helicopter or why.

The FBI said its Evidence Response Team would investigate the incident alongside Air Force officials.

The UH-1N — a workhorse aircraft commonly referred to as the Huey — involved in the incident is assigned to the 1st Helicopter Squadron at Joint Base Andrews, the Air Force said.

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