BART will "staff accordingly" at the Civic Center station with the possibility of a protest Thursday afternoon, BART authorities said.
BART put a warning on its website for passengers to be "advised that protesters may attempt to disrupt train service during August commute periods beginning as early as Thursday, August 11, 2011, in downtown San Francisco BART stations."
Protesters disrupted rush hour commuting on July 11 in response to the killing of Charles Hill by BART police a week earlier. BART police arrested a number of protesters and temporarily closed San Francisco's Civic Center BART station, among others.
BART is most concerned about the safety of the protesters and commuters.
"(Something) as simple as a blow horn and interrupting announcements creates unsafe conditions," BART spokesman Linton Johnson said. "An illegal protest on narrow platforms with fast trains and (electricity); it can make for a deadly combination."
The San Francisco Municipal Transportation Agency also announced it shut down regular cable car service on the Powell Street portion of the Powell-Mason and Powell-Hyde lines at 3:30 p.m. as a precaution of possible disruptions from a protest.
Muni shuttles will be available in their place.
San Francisco police will also have officers on stand-by if a protest were to break out.
Johnson encourages BART passengers to have their eyes and ears open as they commute over the next month.
"Report unsafe behavior, do not confront protestors," Johnson said. "Stay out of harm's way."
BART encourages anyone who sees unsafe behavior to contact (510) 464-7000 or locate an intercom.