McALESTER, Oklahoma - The huge bomb dropped by the U.S. Air Force on an ISIS target in Afghanistan was probably built in McAlester.

The Pentagon says a USAF aircraft dropped the bomb on a cave complex in eastern Afghanistan.

The bomb is officially called a GBU-43 Massive Ordnance Air Blast or MOAB. Its nickname is Mother Of All Bombs.

The GBU-43 is 30 feet long and weighs 21,000 pounds. It contains a non-nuclear warhead, but because of its size creates a blast radius of up to one mile.

The Air Force showed off the huge bomb in March of 2003 in a test in Florida. The weapon is so big it won't fit in any U.S. bombers, so it's carried over the target by an MC-130 aircraft and a parachute drags it over the plane's cargo ramp. 

The Pentagon hasn't released any details about the bomb, but 15 of them were built at the McAlester Army Ammunition Plant in 2003 in the build-up to the Iraq War. 

It was built with an aluminum casing so that its own structure wouldn't limit the force of the explosion of its warhead.

The plant has not said whether it built the MOAB dropped in Afghanistan. However, no other ammunition plant has been known to produce them, and the McAlester plant has a model of a MOAB on display in the front yard of its headquarters building.