Rear Admiral John Kirby, the Pentagon press secretary, said US experts were analysing the video and trying to determine if the bundle was the one the department reported earlier had fallen into the hands of IS fighters or if it was a second bundle in the group’s possession.
Pentagon officials said a US air drop had delivered 28 bundles of military supplies to Syrian Kurdish fighters near Kobani on the border with Turkey on Sunday and reported one had fallen into the hands of IS militants laying siege to the Kurdish town.
The Pentagon later said it had targeted the missing bundle in an air strike and destroyed it.
An Iraqi Kurdish official said 21 tonnes of supplies had been air-dropped to the Kurds in Kobani.
“We’re taking a look at this,” Rear Admiral Kirby said yesterday of the IS video, later shown in BBC news footage. He said the small arms ammunition and weaponry depicted in the video were the kinds of supplies that were dropped, “so it’s not out of the realm of possibility” that it was one of the US bundles.
“We’re still taking a look at it and assessing the validity of it,” he said.
The video posted on YouTube is comprehensively titled “Weapons and ammunition dropped by American planes that fell into areas of Islamic State control in Kobani”. It shows fighters inspecting boxes of hand grenades and rocket-propelled grenades.
One masked gunman holds up a grenade and says: “Booty for the mujahideen.”
US State Department spokeswoman Marie Harf said American officials had seen the video but could not confirm it was accurate. “There’s obviously a lot of false information, particularly propaganda, on the internet and this may fall into that category,” she told reporters.
“We know that part of Isil’s strategy here is to wage a propaganda campaign, and that’s why one of our lines of effort has been delegitimising Isil’s propaganda,” she added, using an acronym previously used by IS, meaning Islamic State of Iraq and the Levant.
The Syrian Observatory for Human Rights, which tracks violence in the Syrian civil war, said two bundles of supplies had fallen in areas controlled by IS fighters.
Rear Admiral Kirby said the Pentagon was only aware of one of the 28 bundles of military supplies falling into the group’s hands, and defended the use of air drops for resupply.
“We are very confident that the vast majority of the bundles did end up in the right hands,” the rear admiral said. “In fact, we’re only aware of one bundle that did not.”
He noted the military previously had used air drops successfully in the fight against IS.
“It’s a very efficient, effective way of getting supplies to a needed population quickly. We did it on Mount Sinjar [to relieve Yazidi minority refugees]. We did it in the town of Amerli for humanitarian purposes. We did it in Kobani to help these guys continue to fight,” he said.