The Pentagon admitted on Wednesday that a bundle of ammunition and weapons dropped over the Syrian border town of Kobane drifted off course and likely ended up in the hands of Islamic State of Iraq and Syria militants instead of Kurdish forces, Al Arabiya reported.
U.S. military officials said the supplies might have gone astray because of the wind, and assured that they were not enough to cause any significant advantage to ISIS militants.
The Syrian Observatory for Human Rights, a Britain-based monitoring group, reported on Tuesday that ISIS had seized at least one cache of weapons airdropped by U.S.-led coalition forces.
Video footage released on Tuesday showed ISIS militants displaying a parachute and wooden crates full of grenades and rockets.
U.S. defense spokesman Army Lieutenant Colonel Steve Warren told reported on Wednesday two caches out of 28 had gone astray but the air force had managed to destroy one. The bundle that went off course and "probably fell into enemy hands," he said.
"One bundle worth of equipment is not enough equipment to give the enemy any type of advantage at all. It's a relatively small amount of supplies. This is stuff [Isis] already has."
Warren said dropping supplies from the air was "extraordinarily complex" and it was "very common" for wind to blow a bundle off its intended target.
"We still know that the vast majority of the resupply bundles that we dropped went to friendly forces and were received by friendly forces," he said.
"There is always going to be some margin of error in these types of operations. We routinely overload these aircraft because we know some bundles may go astray."
Washington has expanded its support to the Kurdish fighters in Kobane in the past week, ramping up air strikes and air dropping supplies from three C-130 cargo aircraft. The ammunition and medical items dropped by parachute were supplied by Kurdish authorities in Iraq, officials said.
ISIS has been trying to seize the town for more than a month now, causing the exodus of some 200,000 people from the area into Turkey. While Kurds are battling on the ground, a U.S.-led coalition is also targeting the militants from the air.