(05-16) 17:57 PDT OAKLAND -- BART service was snarled for more than two hours Thursday morning when a man climbed onto the roof of a busy transfer station in Oakland to wave at train operators, then ran around on a nearby freeway and finally clambered onto the top of three trains before being detained, authorities said.

The man, identified as Rodney Jenkins, 29, of Oakland, was taken away for psychiatric evaluation after officers grabbed him.

"He kept saying over and over again, 'I need help. Please don't hurt me, I need help,' " said BART spokeswoman Alicia Trost.

Jenkins was first spotted climbing onto the roof of the MacArthur BART Station and waving at operators around 5:30 a.m., Trost said.

As police inched closer to him, Jenkins leaped to the top of a train in the station and ran from one end to the other before jumping onto Highway 24.

For almost the next hour, BART police chased Jenkins as he "hid in the bushes for a bit," ran back across the freeway and scaled a barbed-wire fence, and hoisted himself on top of two other stopped BART trains, Trost said.

Michele Boswell was on one of the trains at 6:30 a.m. when Jenkins jumped on.

"I thought somebody was kicking my chair, but it was really the train shaking because there was someone on top," Boswell said.

"We could feel this guy jumping up and down and running back and forth, and we could hear him screaming. He was a big dude."

Boswell said police and the man yelled at each other for several minutes.

Patrick Mah, another passenger, said he heard a foot chase up and down the top of the train.

"The conductor gave us updates every 10 minutes," Mah said, "the most important one being: 'Don't worry. He's unarmed and he won't be able to break into the doors with the power off.' "

Police officers finally tackled Jenkins on top of one of the trains. He slid off and was arrested at 7:15 a.m., Trost said.

Jenkins was taken to a hospital for a psychiatric evaluation. He will eventually be booked on suspicion of misdemeanor trespassing on a railway and interfering with the operation of a train, Trost said.

Jenkins is known to BART police, Trost said. "He is sort of a repeat problem maker on the BART system.

"He was jumping all over the place. He wasn't being hostile - he just wasn't being cooperative."