The San Francisco Chronicle reported that four bodies were covered with tarps outside the Oikos University in East Oakland, while the Contra Costa Times reported a number of possible dead.
Initially police warned that a suspect, described as Korean and in his 40s, was at large, but a short time later, the Oakland Police Department said on Twitter that they had a "possible suspect in custody."
"No imminent public safety threat appears to exist in immediate area," it added. Five ambulances were dispatched to a "multi-patient medical scene," the Oakland Fire Department said on its Twitter feed, citing reports of "multiple stabbing/gunshot victims."
The Oakland Police Department had tweeted that the suspect was "male, Asian, heavy build, khaki clothing, near or in area." The school says on its website that it strives to "provide highest standard education with Christian value and inspiration."