Updated

Ten Philadelphia union members have been indicted for allegedly using illegal means of coercion, including the torching of a Quaker meeting house, to force local contractors to use organized labor.

The federal indictment, which was unsealed Tuesday, accuses members of Ironworkers Local 401 of several crimes, including racketeering and arson. Other alleged crimes include incidents in which union members allegedly threatened or assaulted contractors and damaged construction equipment and job sites.

“While unions have the right to legally advocate on behalf of their members, my office will not tolerate the conduct of those who use violence to further union goals,” U.S. Attorney Zane David Memeger said in a press release. “Union officials and members who commit arson, destroy property, use threats of physical harm, and engage in other acts of violence to extort victims on behalf of their union need to be criminally prosecuted."

According to the indictment, the union members had a "network of individuals," friendly to the union, who helped identify construction projects and job sites were work was being performed without union labor. Then, business agents would approach foremen to imply or explicitly threaten violence, destruction of property, the U.S. Attorney's office said.

The union members even created "goon" squads, comprised of union members and associates, who carried out crimes, the indictment said. One such squad called itself "The Helpful Union Guys," or THUGs, for short.

In December 2012, several union members allegedly cut steel beams and bolts and used torches on structural columns in a Quaker meeting house that was being built in Philadelphia's Chestnut Hill section, reportedly causing $500,000 worth of damage.

Other alleged incidents include using baseball bats to beat a contractor in 2010, and picketing and threatening the contractor of an apartment complex under construction to the point where he relinquished his profits and turned the job over to another construction firm.

A woman who answered a phone call placed to the union by FoxNews.com Thursday night said she had no comment.