WASHINGTON (Reuters) - Six U.S. airmen killed when their plane went down in Laos in 1966 in the Vietnam War have been identified with genetic tests and other methods, the Pentagon said on Tuesday.

They were crew members aboard an AC-47 "Spooky" gunship that was flying a nighttime reconnaissance mission over southern Laos when it went down in flames on June 23, 1966, in a heavily wooded area in Khannouan Province, the Pentagon said.

The six Air Force airmen will be buried as a group at Arlington National Cemetery in Virginia on Friday with full military honors, said Larry Greer, spokesman for the Pentagon's POW/MIA office.

They are: Col. Theodore Kryszak of Buffalo, New York; Col. Harding Smith of Los Gatos, California; Lt. Col. Russell Martin of Bloomfield, Iowa; Chief Master Sgt. Harold Mullins of Denver; Chief Master Sgt. Luther Rose of Howe, Texas, and Chief Master Sgt. Ervin Warren of Philadelphia.

Greer said the cause of the crash remains unknown.

Their remains were recovered by a team of U.S. and Laotian specialists, headed by an American forensic anthropologist, in May and June 1995, Greer said. A local villager in October 1994 had identified an area where personal effects, aircraft wreckage and a crew member's identification tag were found.

The remains were transported to facilities in Hawaii, where scientists used forensic techniques including mitochondrial DNA sequencing, dental remains and X-rays to identify them, Greer said.

"We're very pleased that we're able, even decades later, to help some of the families close this very sad chapter in their lives," Greer said. The Pentagon said 1,849 Americans remain missing in action from the Vietnam War, and more than 88,000 from all wars.