A possible confrontation between New York police and hundreds of Occupy Wall Street protestors loomed Thursday after a Canadian company requested police help while cleaning up three weeks' worth of garbage at the movement's base in Zuccotti Park.

Brookfield Office Properties, an affiliate of Toronto-based Brookfield Properties, owns the park and has asked for police assistance while crews conduct cleanup and do maintenance checks on fixtures and lighting.

A New York Police Department member looks over Occupy Wall Street demonstrators at Zuccotti Park before they start cleaning up their belongings Thursday, the morning after Mayor Bloomberg gave them a message that the park needs to be cleaned. Timothy A. Clary/AFP/Getty

Brookfield also told New York's police commissioner in a letter that neighbours have been deprived of their enjoyment of the park.

“We have received hundreds of phone calls and e-mails from concerned citizens and office workers in the neighborhood,” it said.

As well, Brookfield has raised concerns about health and safety.

Mayor Michael Bloomberg visited the park, not far from the New York Stock Exchange, on Wednesday and told the demonstrators the protests can continue as long as laws are obeyed, but that work crews would start cleaning up trash beginning Friday at 7 a.m. ET.

Some demonstrators said the move was an attempt to drive them out permanently. They said they conduct their own cleanup, and would form a human chain to prevent the clean-up.

On their website, the demonstrators were asking supporters to show up at 6 a.m. to defend against the what it called the forcible closure of Occupy Wall Street.

The plan was to close the park in sections for cleanup. After that, regulations against tents and storing personal property would be enforced.

The protests began on September 17 when a few dozen demonstrators tried to pitch tents in front of the NYSE but were turned out by police.

Since then, the protests against have spread across North America.

The protestors have many causes, but much of the focus is on Wall Street practices and economic inequality.

Protests are planned in several Canadian cities including Toronto, Vancouver, Montreal, Calgary and Edmonton on Oct. 15.