Authorities are searching for a gunman who shot a California Highway Patrol officer during a traffic stop Monday evening.

The shooting happened just before 8 p.m. on the 4500 block of Laurel Canyon Boulevard, according to the Los Angeles Police Department.

The CHP officer attempted to make the traffic stop on the southbound 101 Freeway when the suspect vehicle took an exit and came to a stop on Laurel Canyon Boulevard. At some point during the stop, the suspect opened fire on the officer, who was struck and critically injured.

The CHP officer was transported by ambulance in critical condition to the trauma center at Cedars-Sinai Medical Center.

A heavy law enforcement presence surrounded the shooting scene and the area was sectioned off by crime scene tape.

Law enforcement officers then switched the focus of their investigation to a neighborhood in Van Nuys where the suspect’s vehicle was believed to have been spotted.

An intense search for the alleged shooter took place at an apartment complex on the 7400 block of Haskell Avenue. Video from Sky5 showed dozens of law enforcement officers on the scene, including an armored SWAT team vehicle.

Roads near both the crime scene and the apartment building of the suspected shooter were closed Monday night with no clear timeline for when they would reopen.