COPENHAGEN  - Danish police this weekend spelt out a tough warning about any violent protests at the 12-day UN climate conference starting in Copenhagen on Monday.

"We are ready," Mogens Lauridsen, head of operations at Copenhagen police, told AFP late Saturday.

A Danish police officer walks through a temporary detention center, which can cage hundreds of detainees, during a demonstration in Copenhagen, Thursday Dec. 3, 2009 of the police's latest preparations for the United Nations' Climate summit which is scheduled to start Monday. (Photo/Tariq Mikkel Khan) "We have mobilized enough force from the entire kingdom to handle the heaviest task the modern police has ever been called upon to assume," he said.

"We have anticipated every contingency, including the worst. We are confident, but we expect excesses because there will surely be protesters looking for violence."

Six thousand police -- more than half of all the police in Denmark -- are being deployed in the capital. They could be reinforced to 9,300 men if need be, he said.

A provisional detention center has been set up in a heated former warehouse on the outskirts of the capital with a handling capacity of 350 people.

Around 150 police officials and lawyers are staffing the facility to swiftly process arrests.

Authorities have also sent out over 3,000 letters to residents around the Bella Center, where the conference is taking place, asking them to report any suspicious activity.

Lars Dueholm, a lawyer who lives near the venue, saw from his balcony four French activists unfurl an anti-nuclear banner on Saturday and called the police.

"It is a good initiative but I am not an informer, I am not being paid any money in return," Dueholm told AFP. "What we are afraid of is vandalism and that they will torch our cars."

The December 7-18 conference under the UN Framework Convention on Climate Change (UNFCCC) faces a massive task.

It has to agree the outlines of a new pact that will tame carbon emissions blamed for driving Earth's climate system to potentially catastrophic change.

But the two-year process leading up to Copenhagen has yielded little progress, with divisions between rich nations and poor ones, and friction between advanced economies themselves over burden-sharing.

The yearly UNFCCC conferences are usually the scene for raucous and colorful demonstrations, but rarely for violence.

Known protests are scheduled to be held on Saturday, December 12, and against on Wednesday, December 16, when hardline anti-capitalist militants from Germany say they will try to disrupt proceedings at the venue, the Bella Center.