CHAPEL HILL — Town officials say they were justified in using a tactical squad of officers armed with semi-automatic weapons to remove squatters from a private downtown Chapel Hill building Sunday.

At a press conference Monday, Chapel Hill Police Chief Chris Blue and Chapel Hill Mayor Mark Kleinschmidt said the group was distributing riot literature and could have posed a threat to officers. The group included anarchists, some affiliated with Occupy Chapel Hill, but the group did not represent the Occupy Chapel Hill encampment downtown.

"We believe this was prudent, reasonable, and appropriate given what we knew," Blue said.

Police learned that the building, a vacant car dealership, which once housed University Chrysler and Yates Motor Co., had been taken over by about 70 people Saturday night after an anarchist book fair downtown, Blue said. Several officers entered the building and were approached in a "threatening" manner by some in the group who were wearing hoods and masks and chanting obscenities, he said.

"Based on the known risks associated with anarchist groups, the tactics employed in the Yates building, and the unknown presence of weapons the Chapel Hill Police Department utilized its tactical team to safely secure and enter the building and arrest the illegal occupants," he said.

Police also learned that the occupiers were distributing literature that included instructions on how to flip a police car, break windows, and use fire to create space between police and suspects, Blue said.

"I do not know the intentions of the group with regard to those materials, but they certainly posed a risk to officers who entered the building," he said.

After watching the group for 18 hours overnight, and after the size of the group decreased, police decided to move in with a tactical squad of about 15 officers, with back-up from the Carrboro Police Department and UNC-Chapel Hill public safety officers, he said.

Police wanted to act "quickly and decisively" to clear the building and minimize any potential conflict or violence with demonstrators, Blue said.

"It is not a response we take lightly, but we do feel it was appropriate," he said.

Officers detained about a dozen and arrested seven, charging them with misdemeanor breaking and entering. All seven were released from custody Sunday on a written promise to appear in court.

After the arrests Sunday, police discovered a bag of rocks in the building and some flammable materials, Blue said. No one who was arrested or detained was armed, he said.

Kleinschmidt and Blue read from statements at the press conference and took questions from reporters. A small protest of about six people stood in the back, holding signs that read "cops = army of the rich" and shouted out questions as the two men explained why police swept the building and pointed weapons at those standing outside and inside.

Several statements about why the town responded as it did elicited laughs and hissing from protestors. Town officials threatened to remove several hecklers.

Blue said police are investigating why officers also cuffed and detained two reporters, News & Observer staffer Katelyn Ferral and freelance writer Josh Davis, during Sunday's raid. The News & Observer has requested police rules regarding treatment of the media in protest situations.

Kleinschmidt said the town supports the rights of individuals to protest peacefully but must step in when a group breaks the law.

"The actions were not unreasonable," Kleinschmidt said. "We had breaking and entering of private property downtown. The government has to respond. ... I believe our response to this break-in was the right one," Kleinschmidt said.

Police and Kleinschmidt said they intend to allow the roughly dozen tents in the Occupy Chapel Hill movement to remain outside the downtown post office as long as that group allows access to the building.

Police have no estimate yet on the cost of Sunday's raid.

The former car dealership building at 419 W. Franklin St. is owned by Fayetteville businessman Joe Riddle and has stood empty for many years. The town condemned it Monday as unfit for human habitation.

Blue said police were in contact with Riddle Sunday and that Riddle confirmed the occupiers did not have permission to be in the building. Efforts to reach Riddle for comment Monday were not successful.

The building has a tax value of nearly $786,669, about half the $1.675 million that Riddle paid for it when he bought it in March 2004, according to county land records.

Ferral: 919-932-8746