FORT WORTH, Texas (AP) — Federal authorities have arrested eight men in North Texas on charges they sold women, including at least three juveniles, to have sex with men who had responded to online advertising.

Officials said in a statement Tuesday that the men, ranging in age from 24 to 33, are each facing sex-trafficking charges and are in federal custody.

Authorities say Fort Worth police in March were acting on a tip from the National Center for Missing and Exploited Children when they found a juvenile being sold for sex.

Fort Worth investigators found photos of the girl advertised on the site Backpage.com.

Police also found two other juveniles in a closet of the hotel room where they found the first girl.

Authorities say the men were often violent if the victims didn't comply with orders.