ISIS group terrorists seized at least one cache of weapons airdropped by U.S.-led coalition forces that were meant to supply Kurdish militiamen battling the extremist group in a border town, but may have seized more.

The cache of weapons included hand grenades, ammunition and rocket-propelled grenade launchers, according to a video uploaded by a media group loyal to the ISIS.

The Britain-based Syrian Observatory for Human Rights said the militants had seized at least once cache, but may have seized more.

The Observatory said the caches were airdropped early Monday to Kurds in the embattled Syrian town of Kobani that lies near the Turkish border. Themilitant group has been trying to seize the town for over 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.

On Tuesday, ISIS loyalists on social media posted sarcastic thank you notes to the United States, including one image that said, "Team USA.''

But the badly-aimed weapons drop was more an embarrassment than a great strategic loss. The ISIS militants already possess millions of dollars-worth of U.S. weaponry that they captured from fleeing Iraqi soldiers when the group seized swaths of Iraq in a sudden sweep in June.