WILMINGTON, Mass. (AP) — Two people have pleaded not guilty to charges in what authorities say was an "extensive" human trafficking enterprise that forced women into prostitution and made them live in squalor.

The state attorney general's office said 32-year-old Xiu J. Chen of Medford, and 57-year-old Ronald Keplin of Woburn were arraigned Tuesday in Somerville District Court on charges of human sex trafficking, deriving support from prostitution and keeping a house of prostitution.

Authorities say the pair ran their prostitution business out of massage parlors and spas in Bedford, Billerica, Medford, Reading, Wilmington and Woburn.

Attorney General Martha Coakley says the suspects recruited women along the East Coast and employed them in their businesses, requiring them to work seven days a week.

Coakley says they were forced to live in crowded apartments and sleep on mattresses on the floor.