Anti-police protesters have been lying on train tracks in so-called "die-ins" to campaign against the failure to bring charges against white police officers who killed two unarmed black men.
Large groups in Berkley, California, swarmed roads and public transport Monday night to rally against perceived racism and brutality in the US police force after Michael Brown, an unarmed teenager, was shot by a policeman in Ferguson Missouri, while Eric Garner was allegedly put in an illegal 'chokehold' by on officer until he died.
People can be seen lying on the tracks in front of a Californian Amtrak train, although it is not clear whether the train was originally stationary before they lay down. One tweet claimed 100 people had stopped the train.
Protesters carried placards and called out slogans including "I can't breathe", the final words uttered by Garner before he died, and "black lives matter" which has become a commonly-used phrase in the spreading activism over the police deaths.
Student organisers from The University of Berkeley claim police provoked and attacked protestors on Monday night, using "excessive force and tear gas" according to activism website Alternet, while video shows protestors throwing rocks and bottles at policemen.
Protesters also shut down the Interstate 80 road, as police gathered from far around to control the protests.