Three Mexican nationals were arrested and an assault rifle seized on Thursday on the Tohono O'odham Nation near Casa Grande.
The men were taken into custody, along with the weapon, cell phones and two-way radios in a desert area near Quijotoa, according to a U.S. Customs and Border Protection news release.
Agents searched the location by helicopter from Air and Marine Operations after they took a man into custody for entering the country illegally. The man told authorities that he escaped from armed men who where holding him captive about 30 miles north of the international border, officials said.
Agents searched an area where they believed the man had been held, and encountered the other two men.
All three remain in federal custody pending the outcome of the investigation, said officials.
