U.S. forces dropped the largest non-nuclear bomb ever used in a strike against ISIS in eastern Afghanistan on Thursday, according to Pentagon officials.
The U.S. dropped a GBU-43 bomb, nicknamed the “mother of all bombs,” on ISIS fighters and tunnels and caves used by the terror group in the country’s Nangarhar province, officials said. It was dropped from an aircraft.
White House Press Secretary Sean Spicer said the GBU-43 bomb was used Wednesday around 7 p.m. local time in Afghanistan. He called the weapon “large, powerful” and accurate.
“The U.S. takes the fight against ISIS very seriously,” Spicer said during the daily press briefing.
The White House did not answer reporters’ questions on what led to the strike — a stark contrast to how the administration outlined what led to a missile attack in Syria the week before.
Related: How Big is the GBU-43?
Spicer referred questions to the Department of Defense, declining to “get into details” on whether President Donald Trump had ordered the bombing. NBC reported that presidential authorization is not required for use of the GBU-43.
Military experts said the bomb’s massive blast is terrifying and may have been intended to send a message to ISIS in Afghanistan.
Military officials did not immediately know how many ISIS fighters were killed or if any civilians died in the attack. The military said it took “every precaution” to reduce any possible civilian casualties.
“As ISIS-K’s losses have mounted, they are using IEDs, bunkers and tunnels to thicken their defense,” Gen. John W. Nicholson, the commander of U.S. forces in Afghanistan, said in a statement, referring to the branch of ISIS in Afghanistan and Pakistan.
“This is the right munition to reduce these obstacles and maintain the momentum of our offensive against ISIS-K,” he added.
Hans Kristensen, director of the nuclear information project at the Federation of American Scientists, said that the explosive power of even the smallest nuclear weapon in the U.S. arsenal, the B-61 bomb, is “an order of magnitude” larger than the GBU-43.
The GBU-43 is about half the size of the smallest nuclear weapon ever built, the Davy Crockett nuclear artillery shell, retired in the late 1960’s.
Kristensen said there is a debate inside the defense community on whether to build miniature nuclear weapons.
“We have people arguing for new min-nukes,” he said. “Here you have a case where the U.S. felt all it needed was a conventional whopper.”
“The big unknown with this (GBU-43) bomb is can you get the detonation point close enough to what is in the tunnel,” he said. “How deep does it go in? Does this just destroy the entrance?”