TACOMA, Wash. (AP) - Police said they arrested three people for pushing their way past a line of officers Monday to protest the shipment of Iraq-bound Army equipment through the Port of Tacoma.

Caitlin Esworthy, Walter Cuddeford and Jeffery Berryhill were each being held at the Pierce County Jail, where they were booked shortly after 3 a.m., for investigation of third-degree assault. Bail for each was $10,000 and court appearances were expected Tuesday.

The protest involved about 30 people, participants and police said, and concerned the shipment of Stryker vehicles and other equipment from Fort Lewis.

Tacoma Police spokesman Mark Fulghum said the officers had set up a crowd control line to prevent the protesters from interfering with the military convoy or blocking the road.

The protesters "made contact with the police line and three pushed their way through the line."

No one was seriously injured, he said, but one protester who appeared to charge at an officer was shot in the thigh with a rubber bullet.

Zoltan Grossman, a geography professor at Evergreen State College in Olympia who was observing the protest, said he didn't see what prompted the arrests. Esworthy is an Evergreen State student, and Cuddeford is a Navy veteran, he said.

"There were no rocks, no weapons. People were not carrying anything but signs," Grossman said. "We were on public space, on gravel, and there was a white line that police had told us not to cross. I didn't see any of the protesters cross that line."

Fort Lewis said in a news release the vehicles are being moved in groups of about 25 vehicles in non-peak hours, under escort of military and local police, in support of the 4th Brigade, 2nd Infantry Division's upcoming deployment. The protesters accused the Army of moving the equipment when the fewest people would notice.

"They're sneaking in under cover of darkness because they know how unpopular these are," said T.J. Johnson, an Olympia city councilman and one of the protest leaders.

The protesters planned to rally on an Interstate 5 overpass later Monday to draw attention to the shipments.

Last May, hundreds of protesters objected to similar shipments at the Port of Olympia. Police pepper-sprayed some protesters who pulled down a port gate, and about three dozen people were arrested over several days.