MONUMENT VALLEY, UTAH, DEC. 6 -- Two Navajo tribal policemen have been found dead and their vehicles burned on reservation land near the Utah-Arizona border, prompting a multiagency murder investigation, authorities said.

"Two Navajo panel police cars were down in the bottom of the canyon, both were burned up, and two bodies burned beyond recognition were in the back of one," said San Juan County Sheriff Claude Lacy.

The killings were being investigated by Kayenta, Ariz., police and officers from the Bureau of Indian Affairs, the Federal Bureau of Investigation, and Lacy's office. Spokesmen for tribal police and the FBI in Salt Lake City declined to release details today.

Navajo Department of Public Safety Chief Bill Kellogg identified the victims found Saturday as Roy Lee Stanley, 27, and Andy Begay, 36, both of Kayenta, The Arizona Republic reported today.

Lacy said guns had been taken from the officers and their police vans and bullet holes were found in the vehicles. Although autopsies had not been performed, Lacy said he suspected the two officers had been shot, then placed in the vehicle before it was set on fire.

Police said the officers were killed sometime late Friday or early Saturday.

One of the officers' .357-caliber Magnums was recovered, and investigators were waiting for forensics specialists to arrive before sifting through the ashes, Kellogg said.

The still-smoking vehicles were found by rangers from the Glen Canyon recreation area who were called out about noon Saturday to investigate a report of a burning vehicle in Copper Canyon, about 20 miles west of the Piute Farms Marina on Lake Powell.

Kayenta police said the last communication from the two officers was that they had stopped a truck.