Around 4 p.m. Tuesday protest groups took to the streets in the Lower Haight as part of a demonstration against police brutality and racial injustice in San Francisco. As of 4:20 p.m., protestors had blocked N-Judah and J-Church train service, as well as 22-Fillmore bus service.

The demonstration comes on the heels of the highly controversial George Zimmerman verdict in Florida. Last night in Oakland, demonstrators shut down the Interstate 880 freeway while marching to protest Zimmerman's killing of Trayvon Martin, as well as the shooting of Oscar Grant at Fruitvale Station in 2009.

In San Francisco, protestors are also marching for Kenneth Harding, who reportedly shot himself by accident while trying to evade SFPD officers on a Muni platform in the Bayview in 2011. Today marks the second anniversary of Harding's death.

As of around 4:40 p.m. protestors were starting to clear the area and trains could begin moving again. Protestors were reportedly headed for the SFMTA headquarters at Van Ness and Market Streets, so expect further traffic and transit delays along Market Street:

Update, 5:15 p.m.: the bulk of the protestors have arrived at Market and Van Ness. Alert SF is advising people to avoid the area if possible.

As of around 6 p.m., most of the protests seem to have cleared or are no longer blocking traffic.