Vallejo Police Dept. spokesman Sgt. Jeff Bassett said officers from all over Solano County participated.
"The briefing was in the Coliseum, there were so many officers," Bassett said. "We sent the Solano County Mobile Field Force Unit, but we weren't notified until the last minute, when they realized they needed more officers."
The unit is a multi-jurisdictional force, he said.
The Solano County contingent consisted of eight Vallejo and a half dozen Benicia officers, as well as a dozen each from Fairfield, from the Solano County Sheriff's Office and from a combination of Vacaville, Suisun and Dixon, he said.
The group gathered about midnight Monday, got to Oakland about 1 a.m., deployed for several hours and returned about 9 a.m., Bassett said. They joined some 350 officers from various area agencies, he said.
"It was fairly uneventful," he said. "The only people arrested were those who refused to clear the area, and they pretty much gave up with a whimper. There were no stones, no paint."
Some police were reportedly injured by stones and paint in later violence.
In fact, officers were "a little surprised" to learn the scene deteriorated later in the day in the area they'd cleared across from City Hall, Bassett said.
"There were more than 70 arrests around 5 a.m. Tuesday. The violence requiring a gas response all happened Tuesday evening," he said.
Most of the arrests were for unlawful assembly and illegal camping, according to news reports.
Solano County Sheriff's office spokesman Sgt. Walt Gilliam agreed that the Solano officers didn't expect the violence that came later based on how things went while the local cops where there.

"There were more than 70 arrests around 5 am Tuesday. The violence requiring a gas response all happened Tuesday evening," he said. Most of the arrests were for unlawful assembly and illegal camping, according to news reports. Solano County Sheriff's
A Solano County Superior Court judge will face no charges in connection with an allegation of domestic violence, following completion of an investigation by the State Department of Justice. The Attorney General's San Francisco office
Police arrested a resident, Ronald Sandy, on suspicion of various weapons possession charges, including possession of an Uzi assault weapon and a sawed-off shotgun. Sandy, 49, was booked into Solano County Jail in Fairfield, Benicia police said.
Sandy was booked in Solano County Jail for being a felon in possession of firearms, possession of a rifle with a barrel less than 18 inches long, possession of an assault weapon, and possession of ammunition by a felon, Daley said.
She was charged with being an accessory to murder and for participation in a criminal street gang and booked into Solano County Jail. According to Vacaville Detective Vince Nadashdy, Jordan has no previous arrests and no criminal record.