Two Navajo men charged with the December murder of two Navajo policemen in San Juan County were arraigned Saturday in U.S. District Court for Utah.

Vinton Bedoni, 31, and Ben Atene Jr., 24, both of the Monument Valley area, were arrested Friday afternoon in southern Utah, following what U.S. Attorney Brent Ward called an extensive investigation on the Navajo Indian Reservation.Atene's cousin, Marques Atene, and another Navajo man, Thomas Cly, were arrested early Friday morning and arraigned Friday afternoon.

All four have been charged with first-degree murder and aiding and abetting in connection with the Dec. 5 slaying of Officers Andy Begay and Roy Lee Stanley, whose charred bodies were found in a police van in Copper Canyon, near Lake Powell. The officers were apparently shot before being placed in the vehicle, which was then ignited, according to officials.

U.S. Magistrate Ronald Boyce has appointed attorneys for the four and set a detention hearing for Monday at 4 p.m.

If the men are detained, preliminary hearings will be held within 10 days.