Police are putting on gas masks, apparently preparing to fire tear gas into crowds at 13th Street and Broadway in Oakland. Tensions have been mounting between protesters and roughly 250 Oakland police officers since a gathering of roughly 1,000 people dispersed at about 8 p.m. Some protesters have thrown rocks and a bottle at police. Officers are declaring over a bullhorn that the area is an "unlawful assembly" and will be cleared.

A dozen or so protesters are standing their ground, apparently ready to confront the police. Several dozen other people are taking pictures on their cell phones.

A crowd of about a thousand people dispersed around 8 p.m. from a protest site around 14th Street and Broadway in downtown Oakland. Organizers dismantled a stage that had been set up in the middle of the street, and most of those gathered filed out via 14th and 15th streets.

But a crowd of about 200 people headed straight for a group of police standing nearby. The police moved forward about half a block to meet the protesters, formed lines three-deep and stood with their hands on their billy clubs and their plastic visors drawn over their faces.

Some people in the crowd wore bandanas over their faces, while at least one police officer filmed the confrontation on a video camera. Several people screamed at the police through bullhorns, saying “Fuck the police,” and calling them killers, while the officers stood by impassively and a police helicopter circled overhead.