A CHP officer investigating a suspected alcohol-related crash outside Sebastopol on Thursday afternoon was nearly struck by an oncoming motorist who was himself arrested for suspected drunken driving, authorities said.

In all, two drivers were arrested at the scene — both without valid licenses and believed to be intoxicated, the CHP said.

The cause of the CHP presence in the first place was a 3:34 p.m. crash on Bodega Highway near Spring Hill School Road, where an eastbound Honda Civic had reportedly crossed into an oncoming lane and struck a Honda CRV head on, authorities said.

The driver of the Civic, Rohnert Park resident Santa My, 24, appeared to be intoxicated, the CHP said. He failed field sobriety tests and also had a suspended license because of a previous DUI conviction, the CHP said.

My, who was still on probation, was booked into the Sonoma County Jail, though he later bailed out, jail personnel said.

During the investigation into the crash, a passing motorist stopped to alert officers to a Chevy truck in the area that had been weaving across the road and traveling at approximately 5 mph all the way from Bodega Bay, authorities said.

The truck then made it to the crash scene and nearly hit one of the officers, who was trying to persuade the driver to pull over, authorities said.

The driver, Santa Rosa resident Jose Solorio Hernandez, 22, was unlicensed and failed field sobriety tests, the CHP said. He was arrested for suspected drunken driving and driving without a license, the CHP said.