Occupy D.C. protesters try to cover the McPherson statue with a blue water-proof cloth at McPherson Square in Washington D.C., Jan. 30, 2012. (Xinhua/Fang Zhe)

Defiant Occupy D.C. protesters on Monday vowed to continue with their encampment in the U.S. capital as the deadline for decampment passed.

The U.S. National Park Service last week ordered protesters at two encampment sites -- McPherson Square or Freedom Plaza -- to remove their sleeping bags, pillows and other gear by Monday noon, or they might be arrested.

But as of early Monday afternoon, no one had been arrested at either site, Park Police spokesman Sgt. David Schlosser said at a press conference.

Some protesters agreed to pack up their belongings and leave, but many others refused to decamp by stringing up a huge blue tarp in the middle of the McPherson Square dubbed the "Tent of Dreams."

The White House walked a fine line on the issue. "Our position has been and continues to be that we need to balance First Amendment concerns of the right to demonstrate, the right to speak freely, with public safety concerns and public health concerns," White House press secretary Jay Carney said at his daily briefing Monday.

"We understand that local law enforcement as well as, in this case, the National Park Service and U.S. Park Police are weighing those considerations when they make these decisions. And that's appropriate," he added.

Protesters with the Occupy D.C. movement, an offspring of the widespread Occupy Wall Street movement, had been camping at the two sites for months.

While the enforcement of the ban on encampment in the capital area has so far been largely done in a peaceful way, violence erupted in some other cities.

On Saturday night, police fired tear gas and flash grenades at hundreds of Occupy demonstrators in downtown Oakland, California, as they refused to disperse and tried to seize an empty convention center as the movement's new home.

Oakland police said more than 400 people were arrested and three officers suffered minor injuries. One woman was shot in the back at point-blank range with a beanbag gun and was hurried away by fellow demonstrators.