OAKLAND — An East Bay Regional Park District police officer had a baseball bat and other items thrown at him early Sunday while trying to arrest a Sacramento man who was participating in illegal sideshow activity on Interstate 580 in East Oakland, officials said Tuesday.

The officer was not hurt and was able to make the arrest. Police are seeking the people who threw items at him.

The incident happened about 2 a.m. Sunday in the westbound lanes of Interstate 580, east of Keller Avenue.

EBRPD spokeswoman Carolyn Jones said the officer was driving westbound on the freeway when he saw that all lanes ahead of him were blocked.

He thought it was due to an accident but as he made his way closer he could see a 1999 Ford Mustang doing donuts on the freeway with other people standing on the shoulder near other cars cheering him on, Jones said.

The officer was able to pull the Mustang over to the shoulder where he got out of his patrol car and began asking the driver for his identification.

While he was doing that several people who apparently left the freeway but came back and parked their cars on adjacent Mountain Boulevard came up to the fence separating the street from the highway and began swearing at the officer. The officer radioed for assistance before one man threw a bat at him that was deflected by a tree branch and others in the crowd threw other debris at him, Jones said.

The attackers fled before other EBRPD officers, Oakland police and California Highway Patrol officers arrived on scene.

The Mustang driver, identified as Agustin Bermudez, 23, of Sacramento, was arrested on suspicion of reckless driving, exhibition of speed and driving with a suspended license. His car was impounded.