NEW YORK - Anti-Wall Street protesters are preparing on Friday to block efforts to clean up the Lower Manhattan park where they set up camp nearly a month ago, raising concerns of a possible showdown with authorities.

The private owner of the publicly accessible Zuccotti Park, Brookfield Office Properties, plans to start cleaning at 7 am (1100 GMT) the area where several hundred protesters from the Occupy Wall Street movement have been camping since September 17.

Protesters fear it is an attempt to shut down the movement that has sparked solidarity protests in more than 1,400 cities and plans for global rallies on Saturday in 71 countries, according to Occupy Together and United for Global Change.

Occupy Wall Street has called on protesters to "defend the occupation from eviction" on Friday. Progressive group MoveOn.Org also called on its supporters to "stand with the protesters at the moment when they need us most."

"Be warned, this is a tactic that (New York City Mayor Michael) Bloomberg has used to shut down protests in the past, and a tactic used recently in similar protests throughout Europe," protest organizers said on a Facebook page.

Brookfield said conditions at the park were "unsanitary and unsafe," with no toilets and a shortage of garbage cans. Neighbors complain of lewdness, drug use, harassment and offensive odors from the protesters, Brookfield said.

Brookfield representatives, escorted by police, handed out notices to the protesters on Thursday to tell them that the park would be cleaned in three stages and would reopen for public use consistent with park regulations.

But the rules ban camping, tents or other structures, lying down on the ground, placing tarps or sleeping bags on the ground and the storage personal property - everything the protesters have been doing since they set up on September 17.

"Brookfield respects the rights of free speech, assembly, and peaceful protest," the company has said in a statement.

Police said they will be on hand to ensure public order, but it is up to Brookfield Office Properties to enforce the rules of its park. Police will only become involved if laws are broken or if an official complaint is made by the park owners.

Protesters are upset that the billions of dollars in bank bailouts doled out during the recession allowed banks to resume earning huge profits while average Americans have had no relief from high unemployment and job insecurity.

They also believe the richest 1 percent of Americans don't pay their fair share in taxes.

Hundreds of people have been arrested at rallies in New York and police have used pepper spray. Dozens have also been arrested during the past couple of weeks from Boston and Washington D.C. to Chicago, Austin and San Francisco.

Solidarity rallies have also sprung up at more than 140 US college campuses in 25 states, according to Occupy Colleges.