SAN DIEGO – A man was arrested on suspicion of driving under the influence after he slammed his car head-on into a group of motorcycle riders celebrating their club’s 10th anniversary, killing four motorcyclists and his companion, authorities said Sunday.

The driver, Carlos Ramirez Bobadilla, was among six people injured in Saturday’s crash on a remote desert highway, said California Highway Patrol Officer DeeAnn Goudie. Ramirez, 36, was recovering from hand fractures at a San Diego hospital.

The arrest was made when officers smelled alcohol on his breath about five hours after the crash, Goudie said. Results of a blood test were pending.

It is unclear if the driver’s alleged alcohol consumption contributed to the collision, Goudie said, but he was arrested on a misdemeanor and is not being held responsible for the deaths based on evidence collected so far. Authorities were looking for the driver of a gold Honda Civic who forced Ramirez off the road when trying to pass the motorcyclists on the undivided two-lane highway east of San Diego.

Ramirez, of Mexicali, Mexico, swerved his white Dodge Avenger to the right shoulder to avoid the Honda and then overcompensated by swinging left into oncoming traffic, Goudie said. Ramirez’s speedometer was found stuck at 60 mph, 5 mph below the speed limit.

“It would have been nice if he had just gone off to the right,” she said. “He would have been stuck in the soft sand.”

None of the motorcyclists got the license plate of the Honda driver, described as a man wearing a baseball cap.

“I was the first person on scene that had a uniform on,” Goudie said. “I was being dragged in every direction by frantic people saying, ‘Help this person, help that person.’ “

The CHP withheld names of the five who died, pending notification of family members. They included a husband and wife who were on a motorcycle that was first to be struck.