Authorities excavating the crash site of a U.S. warplane in Laos have expanded their search to look for the remains of two American crewmen who have been missing in action since the Indochina war, a U.S. Embassy spokesman said Friday.

The search team, comprised of 14 U.S. soldiers and a group of Laotian officials, began excavating a 4-by-12-yard area but expanded the site to about 40 by 60 yards after failing to find the remains of the plane's two crewmen, said Ross Petzing, a spokesman for the U.S. Embassy in Thailand.