The campus was on modified lockdown for several hours Wednesday as tactical teams searched for a suspect in an armed robbery in Moreno Valley, KNBC-TV, Los Angeles, reported.
Students and faculty were allowed to leave the campus shortly before midnight, officials said.
The suspect was wanted in connection with an armed robbery that sparked two high-speed pursuits.
Police said three were arrested earlier Wednesday after a robbery at a Moreno Valley pawn shop in which a store employee was shot. Officials said five men wearing ski masks and armed with handguns had robbed the shop.
Nearly 10,000 students were on campus preparing for next week's finals when two men fled onto university grounds, where one was immediately arrested, KNBC said. The other fled into a university building, then reportedly was seen running off campus to a city street.
Reports weren't clear if that suspect was arrested.
The three other men fled away from campus. One was taken into custody. Another hijacked a vehicle and was involved in a high-speed pursuit that ended with his arrest. The third man remained at large, police said.