U.S. drops 'mother of all bombs' in Afghanistan, marking wea

Last Updated Apr 13, 2017 1:22 PM EDT

The U.S. dropped a bomb containing 11 tons of explosives on an ISIS cave complex in Afghanistan's Nangarhar province on the border with Pakistan on Thursday, a Pentagon spokesman confirmed to CBS News' David Martin.

The bomb is officially called a GBU-43 or Massive Ordnance Air Blast (MOAB), leading to its nickname as the "mother of all bombs." The weapon is the largest non-nuclear bomb in the U.S. arsenal and has never before been used in combat.

"The strike was designed to minimize the risk to Afghan and U.S. Forces conducting clearing operations in the area while maximizing the destruction of ISIS-K fighters and facilities," the Pentagon said in a statement, using the term for the Islamic State's Afghanistan branch.

The military also said the U.S. "took every precaution to avoid civilian casualties with this strike."

White House press secretary Sean Spicer said the strike targeted a "system of tunnels and caves that ISIS fighters used to move around freely." He said the U.S. "took all precautions necessary" to minimize civilian casualties.

The Afghanistan strike had been in the works for a number of months, Martin reports. The weapon was brought into Afghanistan specifically for this mission.

General John Nicholson, the commander of U.S. forces in Afghanistan, was required to get permission to use the weapon, but it's unclear how far up the chain of command his request traveled.