Occupy Wall Street protesters camped outside City Hall in Los Angeles have said they plan to hold eviction parties as a deadline to leave the site looms. Overnight, police handed out leaflets informing occupants of the nearly 500 tents that the clock was ticking. Protesters have until midnight local time (0800 GMT) to leave. Los Angeles police chief Charlie Beck said that while his officers would seek to encourage people to leave peacefully, some arrests were likely. \"I have no illusions that everybody is going to leave,\" Mr Beck told the Los Angeles Times on Sunday. \"We anticipate that we will have to make arrests.\" But he said that police officers \"will not be the first ones to apply force\". As the deadline approached, some of those camped outside attended sessions on resistance tactics, including how to stay safe should police begin firing rubber bullets or using pepper spray. But many said they would refuse to leave and were willing to be detained. \"Their plan is to resist the closure of this encampment and, if that means getting arrested, so be it,\" said Will Picard, one of the protesters. \"I think they just want to make the police tear it down rather than tear it down themselves.\" The city\'s mayor has said he hopes to avoid the confrontations between police and protesters that have marred evictions in other cities. Mayor Antonio Villaraigosa, a former union representative, said he hoped for a \"spirit of co-operation\" with those camped out. But his eviction demand earlier this week was dismissed in a statement from the protesters. \"As a collective, Occupy Los Angeles would like to express their rejection of the city of Los Angeles\'s alleged proposal that we leave City Hall,\" protester Jeremy Rothe-Kushel told the Associated Press. \'Proud\' mayor Despite issuing the deadline, Mr Villaraigosa had spoken about the Occupy movement in terms not often heard from elected officials in the US. A protester at the Occupy Los Angeles camp, 22 November 2011 There have been few arrests and little confrontation at the Los Angeles protest \"The movement is at a crossroads,\" he said. \"It is time for Occupy LA to move from holding a particular patch of park land to spreading the message of economic justice and signing more people up for the push to restore the balance to American society.\" However, the camp - which has grown to an estimated 485 tents - was unsustainable because public health and safety could not be maintained, he said. Using a refrain familiar to protesters from New York, where Mayor Michael Bloomberg complained about the health impact of the Zuccotti Park camp, Mr Villaraigosa said City Hall Park had to be cleared, cleaned and restored for public access. \"I\'m proud of the fact that this has been a peaceful, non-violent protest,\" he said. \"I trust that we can manage the closure of City Hall Park in the same spirit of co-operation.\" The Occupy LA camp began on 1 October, shortly after the initial Occupy protest in New York City. Protests in the city have been largely peaceful, with fewer tensions between police and those camping out than in some cities. In Oakland, California, there were several flashpoints between police and protesters, and police also used pepper spray in breaking up an Occupy camp in Seattle, Washington.