Police are searching for a gunman who opened fire Monday on the 405 Freeway, wounding a driver and creating a massive traffic backup.

The California Highway Patrol issued a SigAlert for northbound lanes of the 405 Freeway in Van Nuys Monday as they responded to reports of the shooting.

The incident occurred north of Victory Boulevard. CHP said calls about a possible car-to-car shooting came in around 3:24 p.m.

When authorities arrived, both vehicles involved were gone, though officials said that dispatch received a call that the victim of the shooting was at a Tarzana hospital being treated for a non-life-threatening injury to the upper body and was expected to recover.

All northbound lanes of the I-405 at Victory Boulevard were shut down for several hours while CHP investigated.

Aerial footage from Sky5 showed an officer canvassing the roadway with a bomb-sniffing K-9 and several evidence markers on the ground.

Traffic was backed up into the Sepulveda Pass, with the SigAlert also impacting traffic on the 101 Freeway.

Just after 7:00 p.m., CHP tweeted that all lanes had been reopened.

So far, no arrests have been made and CHP has not released a suspect description.

Anyone with information about this incident was urged to contact the California Highway Patrol.