PORTLAND, Maine (AP) A New Hampshire husband and wife are accused of luring at least 27 Chinese women into the sex trade in Maine, New Hampshire and Vermont.

Court documents indicate 37-year-old Sou Chao Li and his wife, 37-year-old Derong Maio, used a messaging system popular in China to entice women to travel to the U.S. with tourist visas.

A federal indictment charging them with sex trafficking was unsealed upon their arrest on Thursday. They’re due back in court on Tuesday.

The indictment indicates the prostitution involved multiple locations in the three states. The services were advertised on Backpage, a website that was shut down earlier this year.

Their court-appointed lawyers declined to discuss details. If convicted, the most serious charges carry a penalty of up to life in prison.