Weapons, vehicles and equipment worth more than $500 million that the United States gave to Yemen to help them fight terrorism has gone missing.
Officials fear that the military hardware - thought to include 160 Humvees, four Heuy II helicopters, four hand-launched drones, two Cessna aircraft, a specialist surveillance aircraft and four patrol boats - may have fallen into the hands of an Iranian-backed militia or al-Qaeda.
Small arms and other equipment, such as M-4 assault rifles, Glock 9mm pistols, body armour, pairs of night vision goggles and 1.25 million of rounds of ammunition, may also have vanished.
The Pentagon is unable to account for more than $500 million in U.S. military aid given to Yemen, amid fears that the weaponry, aircraft and equipment is at risk of being seized by Iranian-backed rebels or al-Qaeda, according to U.S. officials.
With Yemen in turmoil and its government splintering, the Defense Department has lost its ability to monitor the whereabouts of small arms, ammunition, night-vision goggles, patrol boats, vehicles and other supplies donated by the United States. The situation has grown worse since the United States closed its embassy in Sanaa, the capital, last month and withdrew many of its military advisers.