The trucks carrying fuel, furniture and other goods that roll out of this former U.S. Air Force base ostensibly are bound for Philippine military headquarters in Manila.

Instead, most of the trucks head for warehouses, where their contents are unloaded and transferred through an elaborate fencing network for sale in shops.Filipinos are systematically plundering Clark Air Base, one of the oldest and largest U.S. military installations abroad until it was turned over to the Philippine military in November.

One Filipino officer said looting is common in his country. He and fellow officers provided details, speaking in interviews this week on condition of anonymity because they fear reprisals from commanders.

They said the plundering also has involved Filipino and American troops, as well as local businessmen who see nothing wrong with selling stolen property.

"We wouldn't be selling these items from Clark if base officials were not allowing them out," said Perla Abrea, a merchant. "Why should we be blamed if they allow the items to be taken out?"

Brig. Gen. Leopoldo Acot, a Filipino who is chief of the Clark Air Base command, admits some troops may be involved in the looting but denies senior officers are participating.

The Americans pulled out their last troops on Nov. 26 and since have declined comment on incidents at the base.

U.S. Defense Department spokesman Lt. Cmdr. Greg Hartung said Friday in Washington that "there is no U.S. involvement" in what goes on at the base because it was turned over to the Philippines.

"We wouldn't have any comment on that base now," he said.

Later, a U.S. Air Force official said the military was aware of reports Americans were involved in the looting and sales but had no hard evidence. An investigation is under way, the official said, speaking on condition of anonymity.

Evidence of the pillage can be seen throughout this 106,000-acre base, 50 miles north of Manila, and in nearby shops.

At a former U.S. military housing area near the Sapang Bato community, only the walls and roofs remain.

Gone are the doors, windows, appliances, bathroom fixtures, electrical outlets and wiring. Looters have also made off with water pumps, electrical cables, computers, vehicles and gasoline.

Those goods, many still marked "Property of the U.S. Government," are for sale in markets in Mabalacat, Dau and other communities.

Small-time vandals ordinarily look for toilet bowls, heaters, light switches, hinges and electric wires, which are easy to carry out. Some of the looters can earn up to $4,400 a day in a country with a per capita income of $800 a year.