FOSTER CITY — A man shot and killed by police Friday on Highway 101 near the San Mateo Bridge was carjacking the vehicle he had just collided with when California Highway Patrol officers arrived, authorities said.

The man who died in the commute-hour encounter had not been identified as of late Saturday afternoon, pending notification of his next of kin, according to the San Mateo County Coroner’s Office.

It was just after 5:30 p.m. Friday when CHP officers were called to respond to a report of a traffic collision on northbound Highway 101 near Highway 92, according to the San Mateo Police Department, which is the lead investigating agency in the case.

But as officers were en route to the scene, they were alerted that one of the motorists was armed, police said. And as they arrived, they realized quickly that they were witnessing a carjacking, with the suspect holding a handgun out in the open.

San Mateo police say witness accounts assert that the three CHP officers involved in the confrontation with the suspect “made significant efforts to de-escalate the suspect’s behavior, order him to drop the firearm, and attempt to negotiate with the suspect.”

ABC7 reported that the suspect pointed his gun at the officers, prompting them to fire. The San Mateo police narrative released Saturday, however, did not make mention of what occurred right before the shots, nor did police comment on whether road rage had fueled the initial aggression.

“CHP officers, faced with immediate safety concerns for themselves, witnesses at the scene, and heavy vehicular traffic at rush hour, fired at the suspect, fatally wounding him,” police said.

The man was pronounced dead at the scene. The carjacking victim, identified only as a 55-year-old East Bay woman, was not injured.

Traffic around the site of the shooting was shut down for about seven hours while authorities and crime-scene technicians examined the area.

Additional details were not released Saturday. The three CHP officers who fired their weapons were placed on routine paid administrative leave as San Mateo police, the CHP and San Mateo County District Attorney’s Office launched investigations into the shooting.