This post has been updated.

Authorities removed protesters Saturday evening from an abandoned school in downtown Washington that had been entered by members or sympathizers of the Occupy D.C. movement.

By 7:15 p.m., 11 people had been brought out of the city-owned Franklin School and placed in a police van as protesters pounded on the vehicle from both inside and outside. Two more protesters were discovered hiding in Franklin School Saturday night during a "secondary sweep of the building," bringing the total number arrested to 13.

Earlier, it appeared that about a dozen people went into the three-story building, unfurling a large black banner from the roof of the three-story building, and vowing to stay inside the school until it is converted for community use.

The protesters said they had enough food and other provisions to stay “indefinitely” but police and firefighters broke into a back door about 5:30 p.m. Protesters formed a human chain in an adjacent alley in hopes of preventing other rescue workers from entering the historic structure.

View Photo Gallery: Two groups of demonstrators have entrenched themselves in Freedom Plaza and McPherson Square downtown.

The school at 13th and K streets NW was most recently a homeless shelter, but was shuttered in 2008. Police closed streets in the vicinity.

Protestors wore bandanas over their faces as they dropped the banner from the top of the school about 3 p.m. It read “Public Property Under Community Control.” They waved to about 200 people in a park below who cheered them on.

“They are prepared to hold occupation as long as they have to,” said Ray Valentine, a spokeswoman for Occupy D.C.

A woman inside the building, who declined to give her name, said in a phone interview that the group is busy cleaning up the building so it can be used by the community.

“There is a lot of need for spaces like Franklin,” said the woman, who added that she was born and raised in the District.

Occupy D.C. has called a community meeting for 6:30 p.m. Monday at Asbury United Methodist Church to discuss potential uses for the building with the public.

The school, which opened in 1869, is on the National Register of Historic Places.