Washington, Feb.12 : An audit undertaken by the Government Accountability Office (GAO) in Washington has reported that tens of thousands of assault rifles and other firearms in Afghanistan are at risk of being stolen and landing in the hands of the Taliban because U.S. officials have lost track of them.

The audit found that inventory controls were lacking for more than a third of the 242,000 light weapons donated to Afghan forces by the United States-a stockpile that includes thousands of AK-47 assault rifles as well as mortars, machine guns and rocket-propelled grenade launchers.

There were no reliable records showing what ultimately happened to an additional 135,000 weapons donated by other NATO countries, the report said.

Many of the weapons, supplied between 2004 and 2008, were left in the care of Afghan-run military depots with a history of desertion, theft and sub-par security systems that sometimes consist of a wooden door and a padlock, the report said.

According to the Washington Post, the GAO report says the lax controls extended even to such sensitive equipment as night-vision goggles, which have long given U.S. troops a critical edge in fighting Taliban insurgents in Afghanistan's rugged terrain.

Basic accounting procedures such as recording serial numbers were routinely skipped, placing millions of dollars of weapons "at serious risk of theft or loss," said the GAO report warned.

Lawmakers have begun pressing the Pentagon for explanations in advance of the report's official release. The Pentagon has not responded to the report as yet.