The U.S. dropped its largest non-nuclear bomb in Afghanistan on Thursday, CNN reported. The 21,000-pound bomb, dubbed the “mother of all bombs,” or MOAB, was dropped in eastern Afghanistan province of Nangarhar to target “a series of ISIS caves,” as first reported by CNN and later confirmed to The Daily Beast by a Pentagon official. The name of the weapon is the Massive Ordinance Air Blast Bomb, and it has never been used before in combat, but was famously tested by the U.S. in 2003. CNN said reconnaissance missions were being flown in order to assess the damage.

Gen. John W. Nicholson, the top American general in Afghanistan, had the authority to use that particular munition against the Taliban since he took command in Afghanistan and against ISIS since the Obama administration granted him permission in January 2016. The Pentagon official told The Daily Beast that this had nothing to do with the Trump administration expanding its campaign against ISIS, but was the commanders call. The official, who was briefed on the operation, spoke on condition of anonymity in order to discuss military strategy.