SHIPROCK, N.M. (AP) — Three people were found shot to death in a vehicle on the Navajo Nation, the FBI said Monday.

FBI special agent Bill Elwell said the "execution-style" killings occurred along a dirt road just east of Shiprock. A motive was not immediately known.

The victims were two unidentified men and a woman, Vickie Benally, 26, of nearby Farmington.

Elwell said it appeared all three were shot while inside the parked vehicle, which was struck by several bullets. It was unclear how many assailants were involved.