The United States Department of Defense said on Tuesday that it is “not out of the realm of the possible” that some of the weapons and ammunitions airdropped by the U.S. military near Kobani had fallen into the hands of the Islamic State group. Earlier on Tuesday, the militant group released a video showing a cache of weapons, apparently dropped by the U.S., in their possession.

“They are certainly of the kinds of material that was dropped,” Pentagon spokesperson Rear Admiral John Kirby said on Tuesday, referring to the weapons showed in the ISIS video. “We’re taking a look at this…and when we have something definitive that we can provide in terms of an assessment on that, we'll do that.”

Kirby, however, added that he is “very confident” that most of the airdropped weapons had reached the Kurds battling the Islamic State group in Kobani. “In fact, we're only aware of one bundle that did not,” Kirby said.

The video released by the Islamic State group shows a large consignment of packages containing hand grenades and rounds for small rockets wrapped in clear plastic attached to parachute cords. The Syrian Observatory for Human Rights also confirmed that ISIS had seized at least one cache of weapons meant for the Kurds, according to media reports.

The U.S. military had delivered nearly 30 packages containing weapons, ammunition and medical supplies on Sunday, in an attempt to “enable continued resistance against ISIL's attempts to overtake Kobani,” according to a statement by the United States Central Command, or CENTCOM, released Sunday.

Redur Xelil, a spokesperson for the YPG, a Kurdish militia, had confirmed on Monday that Kurdish fighters had received the weapons, and said that they would “help greatly” in the battle against the Islamic State group in Kobani, according to an Al Jazeera report.

The situation in the Syrian border town, meanwhile, continues to remain “tenuous,” Kirby said on Tuesday.

“We do assess that Kurdish forces in the city are in control of the majority of the city. I would hesitate to put a number figure on that, but we do believe that they are in possession of the majority of it,” he said, adding that the U.S.-led coalition had continued to conduct airstrikes in the region.