PHNOM PENH, Cambodia (AP) _ Four bodies that may be those of foreign journalists believed executed by Khmer Rouge guerrillas 22 years ago were flown to Honolulu on Wednesday for analysis, U.S. officials said.

They were dug up from a river bed 25 miles south of Phnom Penh. Two were found with their hands tied behind their backs, said a U.S. official who spoke on condition of anonymity.

U.S. investigators say preliminary findings suggest the remains may belong to four of the five journalists working for the American networks NBC and CBS who disappeared while covering the Indochina War.

On the tarmac at Phnom Penh airport, U.S. servicemen carried the aluminum caskets - draped in a white sheet out of respect for the dead - onto an Air Force plane bound for Hawaii. An honor guard saluted.

The remains were well-preserved and virtually complete, so prospects for identification are good, said Madeleine Hinkes, an anthropologist with the Army Central Identification Laboratory.

The remains ''showed some signs of physical violence,'' she said.

The missing NBC journalists are American correspondent Welles Hangen, French cameraman Roger Colne, and Japanese soundman Yoshihiku Waku.

The CBS journalists are cameraman Tomoharu Ishii and soundman Tojiro Sakai, both Japanese.

The U.S. source said two of the bodies found were Caucasian and two were Asian.

Foreign Minister Hor Nam Hong promised in an interview that his government would fully cooperate with attempts by the United States, Japan and other countries to account for missing foreign nationals in Cambodia.

The journalists had been driving along Highway No. 3 on May 31, 1970, covering a major battle, when their lead vehicle was hit by a grenade that killed three CBS journalists.

At gunpoint, the Khmer Rouge marched the five survivors into the jungle. They were never heard from again.

Peter Chhun, an NBC news editor who has been investigating the case, says local villagers told him they saw a combined force of Communist Vietnamese and Khmer Rouge guerrillas capture the journalists. The Khmer Rouge men beat them to death, the villagers said.

''Nobody knows for sure why they were killed,'' Chhun said.

Many years later, U.S. investigators began focusing on a site pointed out by a man who said he had dug the graves of the journalists. The Pentagon sent a team to unearth the site.

U.S. military experts working with Cambodian officials dug up the area for 13 days earlier this month but came up with nothing.

A day after the team left, they heard that villagers there had found some remains. The investigators returned, resumed digging and found the remains.

No trace of the fifth body was found.

In all, 19 foreign journalists are listed as missing from the wars in Vietnam, Laos and Cambodia, which all ended in Communist victories in 1975.

Cambodia's Khmer Rouge toppled the U.S.-backed Lon Nol government in April 1975, then killed hundreds of thousands of Cambodians during a reign of terror.

Vietnam invaded Cambodia in late 1978 and ousted the Khmer Rouge, who fought a guerrilla war against the government Vietnam installed until a recent peace treaty that allowed the Khmer Rouge to return to Cambodian politics.