WASHINGTON -  The United States has dropped the largest non-nuclear bomb on a tunnel complex in Afghanistan, the US military said.

The use of the GBU-43/B is a first for the battlefield, and was dropped in Nangarhar province on Thursday. The target was a tunnel complex in Achin district being used by the ISIS-Khorasan group.

There were no immediate reports of deaths or injuries from the massive blast.

Known as the "Massive Ordnance Air Blast," the bomb has been nicknamed "Mother of All Bombs." Developed in 2003, the bomb has been tested but never used against an enemy. The bomb is 30-feet long and weighs 21,000 pounds.

"As ISIS-K's losses have mounted, they are using IEDs, bunkers and tunnels to thicken their defence," General John "Mick" Nicholson, commander of US Forces-Afghanistan said in a statement.

"This is the right munition to reduce these obstacles and maintain the momentum of our offensive against ISIS-K."

On Saturday, Staff Seargant Mark R De Alencar was killed in Nangarhar province while fighting the ISIS-Khorasan group, an ISIS affiliate that operates in Afghanistan. Nangarhar province, on the eastern border near Pakistan, has been a base of operations for ISIS since 2015, the military said.

"Daesh [ISIS] seek to use the area to train, equip, disseminate propaganda, and expand their control over innocent Afghans," US Forces-Afghanistan said in September.

The military statement said that the bomb was dropped from "a US aircraft," and the strike "was designed to minimise the risk to Afghan and US Forces conducting clearing operations in the area while maximising the destruction of ISIS-K fighters and facilities."