With additional reporting by Andrew Jones.

Hundreds of protesters at "Occupy Oakland" were facing arrest in the early hours of Tuesday morning as 100 or more police officers closed in on their location.

Local media reports indicated that hundreds of police showed up wearing riot gear around 4:40 a.m. and proceeded to surround the small tent city at Frank H. Ogawa Plaza, which protesters have taken to calling "Oscar Grant Plaza" in honor of a young man who was gunned down for no apparent reason by a Bay Area Rapid Transit (BART) police officer almost three years ago.

Officers closed in on the camp within 20 minutes after donning gas masks, firing tear gas, rubber bullets and beanbags into the protest and lobbing flashbang grenades. "Dozens" were arrested, according to The San Francisco Chronicle.

The Okaland Tribune reported that police successfully demolished the camp and cleaned out all their tents, a medical desk, a makeshift kitchen and more, after having declared the whole site a "crime scene," even though no other crime than an "unlawful assembly" had occurred.

Live video from just outside the park appeared to show officers leaving the scene just before 6 a.m. PST. Later reports indicated that officers moved to a second "Occupy" site at Snow Park.

These same protesters just two days earlier forced a Chase Bank branch to shut down after they marched into the lobby chanting, "Chase got bailed out, we got sold out."

Updated: According to NBC Bay Area, Oakland's mayor Jean Quan issued the following statement:

"Many Oaklanders support the goals of the national Occupy Wall Street movement. However, over the last week it was apparent that neither the demonstrators nor the City could maintain safe or sanitary conditions, or control the ongoing vandalism."

The San Francisco Chronicle has reported that 85 people have been arrested.

"I am very pleased with the way things went," interim Police Chief Howard Jordan said at a news conference. "In the end, I think we allowed people to exercise their rights to free speech and free assembly."

Protesters have indicated on their Twitter page that at least 500 officers were on hand for the raid. They also said that officers from at least three other cities joined the Oakland force for the crackdown.

An emergency demonstration is being planned by the Oakland protesters at 4 PM local time at the plaza.

The following video is a live stream provided by the protesters.

Live video for mobile from Ustream

Photo: Flickr user dignidadrebelde.