"They were all very small fires, but at the peak we had five engines out of service dealing with those small fires," San Jose Fire Captain Mitch Matlow.
Sky 7 was above the south downtown area around 6:30 a.m.
Flames could be seen coming from dumpsters and trash cans in several different spots.
San Jose firefighters say they were called to nine or 10 in the area.
Matlow said, "The biggest concern is that someone is going to get hurt."
Alpha Phi Alpha fraternity house at San Jose State suffered minor damage after arsonist lit garbage can on fire and pushed it into building. #SJSU police say several other similar fires set around same time this morning in downtown area. No one was hurt. pic.twitter.com/j6OKo0nXqE— Matt Keller (@MattKellerABC7) May 24, 2018
San Jose firefighters say arson investigators are looking into the cause.
San Jose State police say one fire landed in their jurisdiction.
The Alpha Phi Alpha Fraternity House on East San Salvador, across from the campus, suffered some damage after a garbage can was lit on fire and pushed up against the building.
An alert was sent out to students warning people about the arson and several others set in the downtown area.
A San Jose State police captain said this fire was similar to the others set in the area. The arsonist would push up a dumpster or garbage can against buildings or fences.
San Jose State police say the only information they have on a suspect is he was driving a silver or grey Nissan pick-up truck.