The National Lawyers Guild says it has obtained a court that allows Occupy Wall St. protesters to return with tents to a New York City park.

The guild says the injunction prevents the city from enforcing park rules on Occupy Wall Street protesters.

Mayor Michael Bloomberg says the city knew about the court order but has not seen it. He says the city plans to go court immediately.

Zuccotti Park was cleared overnight so that crews could clean it. Bloomberg says that was done "to reduce the risk of confrontation."

He says the city had planned to allow the protesters back in the park after it was cleaned. Under the city's plans, protesters would not be allowed to use tents, sleeping bags, or tarps and would have to follow all park rules.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

Hundreds of police officers in riot gear raided Zuccotti Park early Tuesday, evicting dozens of Occupy Wall Street protesters from what has become the epicenter of the worldwide movement protesting corporate greed and economic inequality.

About 70 people were arrested, including some who chained themselves together, while officers cleared the park so that sanitation crews could clean it.

Protesters at the two-month-old encampment were told they come back after the cleaning, but under new tougher rules, including no tents, sleeping bags or tarps, which would effectively put an end to the encampment if enforced.

Mayor Michael Bloomberg said in a statement Tuesday that the evacuation was conducted in the middle of the night "to reduce the risk of confrontation in the park, and to minimize disruption to the surrounding neighborhood."

He said after the cleaning, protesters would be allowed to return but "must follow all park rules."

"The law that created Zuccotti Park required that it be open for the public to enjoy for passive recreation 24 hours a day," Bloomberg said. "Ever since the occupation began, that law has not been complied with, as the park has been taken over by protesters, making it unavailable to anyone else."

Concerns about health and safety issues at Occupy Wall Street camps around the country have intensified, and protesters have been ordered to take down their shelters, adhere to curfews and relocate so that parks can be cleaned.

At about 1 a.m. Tuesday, New York City police handed out notices from Brookfield Office Properties, owner of Zuccotti Park, and the city saying that the park had to be cleared because it had become unsanitary and hazardous. Protesters were told they could return in several hours, but without sleeping bags, tarps or tents.

Hundreds of former Zuccotti Park residents and their supporters were marching along Lower Manhattan before dawn Tuesday and threatened to block Broadway during the morning rush hour.

Others gathered near Foley Square, just blocks from Zuccotti Park, where they can't get arrested.

Paul Browne, a spokesman for the New York Police Department, said the park had been cleared by 4:30 a.m. and that about 70 people who'd been inside it had been arrested, including a group who chained themselves together. One person was taken to a local hospital for evaluation because of breathing problems.

Police in riot gear filled the streets, car lights flashing and sirens blaring. Protesters, some of whom shouted angrily at police, began marching to two locations in Lower Manhattan where they planned to hold rallies.

Some protesters refused to leave the park, but many left peacefully.

Ben Hamilton, 29, said he was arrested "and I was just trying to get away" from the fray.

Rabbi Chaim Gruber, an Occupy Wall Street member, said police officers were clearing the streets near Zuccotti Park.

"The police are forming a human shield, and are pushing everyone away," he said.

Hundreds of police officers surrounded the park in riot gear with plastic shields across their faces, holding plastic shields and batons which were used on some cases on protesters.

Police also came armed with klieg lights, which they used to flood the park, and bull horns to announce that everyone had to clear out.

Jake Rozak, another protester, said police "had their pepper spray out and were ready to use it."

Notices given to the protesters said the park "poses an increasing health and fire safety hazard to those camped in the park, the city's first responders and the surrounding community."

It said that tents, sleeping bags and other items had to be removed because "the storage of these materials at this location is not allowed." Anything left behind would be taken away, the notices said, giving an address at a sanitation department building where items could be picked up.

Alex Hall, 21, of Brooklyn, said police walked into the park "stepping on tents and ripping them out."

Before dawn, sanitation plows and trucks were lined up on Broadway ready to roll into the park and remove what was left of the debris.

On Monday, a small group of demonstrators, including local residents and merchants, protested at City Hall. In recent weeks, they have urged the mayor to clear out the park because of its negative impact on the neighborhood and small businesses.

Occupy encampments have come under fire around the country as local officials and residents have complained about possible health hazards and ongoing inhabitation of parks and other public spaces.

Anti-Wall Street activists intend to converge at the University of California, Berkeley on Tuesday for a day of protests and another attempt to set up an Occupy Cal camp, less than a week after police arrested dozens of protesters who tried to pitch tents on campus.

The Berkeley protesters will be joined by Occupy Oakland activists who said they would march to the UC campus in the afternoon. Police cleared the tent city in front of Oakland City Hall before dawn Monday and arrested more than 50 people amid complaints about safety, sanitation and drug use.