Police say up to 21 protesters from a nearby tent city in Nanaimo, B.C., were removed and charged with mischief after they occupied a closed elementary school in the area.

Some of them gathered on the building's roof, shouting "Fight for justice! Fight for homes!"

The tent city residents set up their camp last May to protest the lack of housing in Nanaimo, and to provide a place for them to live

Const. Gary O'Brien said officers removed the protesters from Rutherford Elementary School — including from the roof — with the help of firefighters and a tactical response team early Saturday afternoon.

O'Brien said the protesters had been at the school since about 4 a.m. Friday. He said the school district contacted police to have the protestors removed. 

Officers arrested the protestors for breaking and entering and mischief, O'Brien said, and took them to a local detachment. 

He said school officials are currently assessing the school for any damage before boarding it up again. 

On Twitter, the protesters said "an angry mob" opposed to the protest had gathered at the school, at times prompting a tense exchange. 

O'Brien confirmed up to 400 people were on site to witness the protest, adding that most of them were supportive of police.

Protesters call for more housing options
Like many cities in B.C., Nanaimo has been the site of a contentious homeless camp.

In late September, B.C. Supreme Court granted the City of Nanaimo an injunction so it could remove the camp. 

On Friday, B.C. Housing Minister Selina Robinson said in a written statement that the province has bought property to build 80 units of temporary workforce modular housing, adding to another 90 units it will build on land provided by the city. 

The ministry said the homeless camp will be closed in phases while the residents are transitioned into the modular homes.