U.S. Marines joined an international effort to deliver aid and medical care to nearly 650,000 Indonesians displaced by a devastating earthquake, as hopes faded of finding more survivors. Two U.S. Marine cargo planes carrying a mobile field hospital landed Tuesday in Yogyakarta, closest to the quake area in central Java, after cracks in the airport runway were patched, the Associated Press reported. A disaster assistance response team from the U.S. Agency for International Development is being readied and the amphibious assault ship USS Essex, which has extensive medical facilities, is en route to the area, White House deputy press secretary Dana Perino said. The United States also increased its aid contribution to $5 million. The United Nations said at least 21 other countries have joined the effort to help those left homeless by Saturday's magnitude-6.3 quake, which killed more than 5,800 people. An estimated 647,000 people were displaced by the quake, nearly a third of them homeless and the rest staying with relatives, said Bambang Priyohadi, a senior provincial government official. The government said Wednesday the temblor destroyed more than 135,000 homes, reducing them to piles of bricks, tiles and wood in less than a minute. Priyohadi based the displaced figure on the number of homes destroyed and a family index of 4.8 people per house.