Officers responded to a report of an armed robbery in the 2200 block of 83rd Avenue shortly after 11 a.m., Oakland police spokeswoman Johnna Watson said.
Watson said the robbery victim was on the street when two suspects armed with guns and possibly a knife approached him.
Officers arrived and there was a brief hostage situation involving one of the suspects at a building in the 2000 block of 82nd Avenue, police said.
The suspect involved in the hostage situation has been taken into custody, but the second suspect remained at large as of 1:45 p.m.
More than a dozen police cars could be seen driving around the neighborhood and some intersections remained closed.
Two schools in the area were briefly locked down because of the search -- East Oakland Pride Elementary and the Aspire College Academy on Atherton Street.
Oakland Unified School District spokesman Troy Flint said East Oakland Pride went on lockdown at 11:20 a.m., and that the lockdown was lifted shortly after noon.
"Since the armed suspects were in the area, it just made sense to take that precaution," Flint said.