A "No Justice, No BART" spokesman, who identified himself as Krystof, said the group will protest Thursday at 5 p.m. outside the fare gates at Powell Street station.
Krystof said the group expects about 200 people to take part in the demonstration and said that if BART police attempt to interrupt the protest, the group would move to different stations.
No Justice, No BART originally formed after the Jan.1, 2009 BART police shooting of Oscar Grant in Oakland and organizers today said they will continue to protest until their demands are met.
One demand, Krystof said, was that transit officials disband the BART police.
"There's an epidemic of police brutality in our communities," No Justice, No BART organizer Cat Brooks said. "We will not be silent, we will not shut up, we will not go away."
Organizers are calling the Thursday protest "Spare the Fare" and are asking commuters who cannot take part in the protest to show their support in another way. Krystof said BART police often open the fare gates to commuters during a protest, allowing riders to enter for free. Organizers today asked commuters to take advantage of this and to begin their commutes at Powell Street station on Thursday as a show of support.
No Justice, No BART staged an Aug. 11 protest against the BART police shooting of 45-year-old Charles Hill in July.
During that protest, BART cut off cellphone service at several San Francisco stations, a decision that spurred hacker group "Anonymous" to organize a series of protests, including this evening's demonstration at the Civic Center station.
Krystof today said that No Justice, No BART is not affiliated with Anonymous and is not planning any events in conjunction with the hacker group.
Although the two activist groups have been operating separately, No Justice, No BART said it supports Anonymous' efforts.
BART deputy spokesman Jim Allison said BART did not alert passengers about today's protest as it has during the past three weeks, partly because fewer passengers are expected due to the holiday.
"We'll do whatever we can to keep everyone safe and hopefully keep trains on time," he added.