A joint Lao-U.S. excavation of U.S. warplane crash sites in Laos successfully uncovered remains and other evidence of the deaths of a number of missing Americans, official Vientiane radio reported Thursday.

"Implementing the Lao government's humanitarian policy toward families of U.S. soldiers missing in action during the war, a Lao technical team and a U.S. technical team from an MIA search center in Hawaii carried out excavations on two sites of U.S. plane crashes," the radio said.Unlike Vietnam, Laos never returned any American prisoners after the war. The United States lists more than 500 Americans as missing in Laos.