The U.S. just dropped its largest non-nuclear bomb in Afghanistan

The U.S. just dropped a 21,000-pound bomb on an ISIS target in a remote area of northeast Afghanistan, according to CNN’s Barbara Starr and confirmed by the Pentagon.

The Massive Ordnance Air Blast Bomb (MOAB) was dropped in Afghanistan’s remote Nangarhar province near the Pakistan border at 7 p.m. local time, the Pentagon confirmed Thursday afternoon. The target was an ISIS tunnel complex, military sources told CNN.

It’s the first time a MOAB (nicknamed “the mother of all bombs”) has been used in a battlefield setting since its creation. Developed during the Iraq War, the MOAB is the U.S.’ most powerful non-nuclear bomb. It is a “concussive bomb,” meaning it detonates above ground rather than penetrating hardened defenses.

“This is the right munition to reduce these obstacles and maintain the momentum of our offensive against ISIS-K,” Gen. John W. Nicholson, commander of U.S. forces in Afghanistan, said in a statement.

White House Press Secretary Sean Spicer discussed the bomb drop during Thursday’s press briefing. “We targeted a system of tunnels and caves that ISIS fighters used to move around freely, making it easier for them to target U.S. military advisers and Afghan forces in the area,” he said.

ISIS is hardly the strongest terror group in Afghanistan — the Taliban remains dominant— but it has expanded since entering the country in 2014 and is a growing concern for the Afghan government and the U.S. military and its allies. The U.S. significantly increased airstrikes in Afghanistan in 2016 — a trend that has continued in the first months of President Trump’s administration.

ISIS claimed responsibility for a suicide attack Wednesday in the capital Kabul that killed at least five people and injured 10 more.

As well as fighting the country’s growing ISIS affiliate, the U.S. remains deeply entrenched in a drawn-out war with the Taliban. In February U.S. Gen Nicholson requested “a few thousand” additional troops be deployed to help beat back a strengthening Taliban. “It would enable us to thicken our advisory efforts across the Afghanistan mission,” Nicholson told the Senate armed services committee.

Updated: 2:45 p.m. ET