Authorities are investigating the shooting of a New York state trooper on Long Island’s Southern State Parkway, and the man they believe responsible remains at large.

According to investigators, the trooper was patrolling the westbound highway near Exit 17 in West Hempstead shortly before midnight when he noticed a black sedan illegally parked on the side of the road.

He stopped behind it, noted the license plate and got out of his car. As he approached the rear of the black sedan, investigators said, the officer heard a series of gunshots and realized he had been shot in the leg.

He retreated behind his vehicle as the suspect drove off. He was then able to treat his own injuries before being transported to hospital, where he was last reported to be in stable condition. He required surgery, authorities said.

The suspect fled the scene in possibly a Dodge Charger, bearing New Jersey temporary tag NJ 997636T, officials said.

State police say they are conducting an “all-out” search for the vehicle and are asking anyone with information to call authorities.

The highway was closed in the area for a period of time to facilitate the investigation.

Anyone with information can call 631-756-3300.