A 21,000 pound bomb has been dropped in Afghanistan.

FOX's Rachel Sutherland reports from Washington:

Days after a Green Beret died fighting ISIS in eastern Afghanistan, the U.S. has dropped what's called the "Mother of all Bombs" on the region:

(Spicer) "We targeted a system of tunnels and caves that ISIS fighters used to move around freely."

White House Press Secretary Sean Spicer:

(Spicer) "The United States took all precautions necessary to prevent civilian casualties."

The bomb, the largest non-nuclear weapon in the Pentagon's arsenal, was dropped from an Air Force cargo plane.

In Washington, Rachel Sutherland, FOX News.

Follow Rachel Sutherland on Twitter: @SutherlandFOX