BART reported delays in downtown Oakland on Thursday morning because of a person on the tracks.
The transit agency issued a service advisory shortly before 10:30 a.m. about the problem, which is affecting service in all directions through Oakland.
A day earlier, BART service through the Transbay Tube resumed after halting due to another person on the tracks near Embarcadero Station Wednesday evening, the agency said at 6:19 p.m.
A person was first reported on the tracks around 4:45 p.m. The disruption caused major delays in both directions as the tunnel between San Francisco and the East Bay was closed.
By 5:20 p.m., East Bay bound trains were turned around at Embarcadero, and BART had to advise people traveling between San Francisco and the East Bay to find alternative transportation.
Normal Caltrain service was temporarily halted Thursday morning in San Francisco after a man climbed up into the overhead wires near the station at Fourth and King streets.
San Francisco emergency officials initially issued an alert shortly after 6 a.m. about police activity affecting Caltrain operations.
Caltrain officials said no trains were going in or out of the station while police tried to convince the man to come down from the wires. Southbound trains were departing from the 22nd Street station.
About 9 a.m., the man was taken into custody and train service resumed as normal from Fourth and King streets within the hour afterward, according to Caltrain.
No other details were immediately available about the man in custody.