The private law office of Vallejo Mayor Osby Davis caught fire overnight Saturday and fire investigators quickly declared the fire suspicious.
Vallejo Fire Chief Paige Meyer says the fire, reported around 1:30 a.m. Saturday, damaged a waiting room and office area before firefighters put the fire out around 1:45 a.m. Meyer called the fire very "suspicious."
Vallejo police called in both the FBI and the ATF, and said they are treating the fire as a possible case of domestic terrorism.
NBC Bay Area has learned police have surveillance video from a building across the street . That video is being processed to assist in the investigation.
Authorities are asking anyone who may have been in the area at the time and seen anything suspicious to contact police or fire officials.
The offices where the fire broke out are across the street from the Solano County Superior Courthouse.
The fire chief himself called Mayor Davis to tell him about the blaze. Davis arrived on the scene while the fire was still burning.
"I plan to keep going," Davis told the paper. "This is a bump in the road, a temporary hurdle. And we'll get past it and continue to do what we need to do.