The Powell Street BART station was shut down late Sunday due to a suspicious package investigation, according to BART officials.
Police responded to the station a little after 7 p.m., and trains out of the station were holding, BART said.
The issue was resolved at about 8:15 p.m., BART said.
Initially, the police activity caused a major delay on the San Francisco line in the SFO/Millbrae and East Bay directions.
Mutual aid was being provided by MUNI bus lines 5, 6, 7, 9, 21, 31 and F.