Chicago Police arrested several protesters Tuesday afternoon at a Chicago Teachers Union sit-in outside the headquarters of developer Sterling Bay on the Near West Side.

Officers arrested nine people shortly after 1 p.m. at the protest at Fulton West, an office building in the 1300 block of West Fulton Street, according to Chicago police.

Police spokesperson Jessica Alvarez said the charges would likely be criminal trespass to property.

The CTU said in a tweet that nine union members were arrested at the protest.

Minutes earlier, the CTU had a scheduled news conference at that location to draw attention to tax money the union says is diverted from schools to developers like Sterling Bay.

In a tweet, Sterling Bay said the arrests were made “at the request of Fulton West’s new management and ownership, not Sterling Bay.”