Throngs of anti-Wall Street protesters braced for eviction Tuesday night from their encampment outside Los Angeles City Hall, as word spread by broadcast news reports and the Internet that a police raid was imminent.

Hundreds of Occupy LA activists, joined by supporters streaming into the area in a show of solidarity, stood crowding the lawn, sidewalks and streets around City Hall awaiting the expected arrival of police.

Live local television news reports showed large numbers of police, patrol cars, buses and other vehicles massing at Dodger Stadium, a few miles away, in what appeared to be a major staging operation.

Twitter traffic among Occupy protesters was abuzz with unconfirmed reports that a police raid on the camp would be taking place within hours.

The Los Angeles encampment, which officials had tolerated for weeks even as other cities moved in to clear out similar compounds, is among the largest on the West Coast aligned with a 2-month-old national Occupy Wall Street movement protesting economic inequality and excesses of the U.S. financial system.

Protesters began moving onto the City Hall park on Oct. 1, and within weeks the encampment had grown to include as many as 500 tents, with between 700 to 800 full-time residents.

That number had diminished sharply since Mayor Antonio Villaraigosa announced last week that he wanted protesters to pack up their tents and other belongings and clear out by first thing Monday morning or face forcible removal.

That deadline came and went, however, with police closing in on the encampment early on Monday when protesters started to block traffic. But the force of about 300 officers sent in at that time stopped short of clearing the camp and withdrew once they had reopened streets for Monday commuters.

Four people were arrested on suspicion of being present at an unlawful assembly.

Since then, the status of the encampment had remained in a state of limbo. Attorneys for Occupy LA asked a federal judge for a court order barring police from shutting down the camp, arguing city officials had violated their civil rights by ordering it dismantled. But the judge has made no ruling.

Villaraigosa initially had welcomed the protesters, going so far as to supply them with ponchos for inclement weather. But as city officials complained of crime, sanitation problems and property damage they blamed on the camp, the mayor decided the group had to go.

He issued his eviction notice last Friday after talks on a plan to induce the protesters to leave voluntarily collapsed, setting the stage for the latest showdown between leaders of a major U.S. city and the Occupy movement.

The mayor has promised to find alternative shelter for homeless people who had taken up residence at City Hall and were estimated to account for at least a third of those camped at City Hall.

(Writing and additional reporting by Steve Gorman; Editing by Cynthia Johnston)