
The United States dropped its largest non-nuclear weapon on Thursday after it targeted an ISIS network of caves and tunnels in eastern Afghanistan.

The blast killed 36 militants as it destroyed three underground tunnels as well as weapons and ammunition, a spokesman for the Afghan Ministry of Defense said.

No civilians were hurt, he added.

U.S. forces used a 30-foot long, GPS-guided GBU-43 bomb, at around 7.30pm local time in the Nangarhar Province.

The weapon weighs a staggering 21,600 pounds.

It is known as the 'Mother Of All Bombs' – a play on 'MOAB,' an acronym that stands for 'Massive Ordnance Air Burst.'

A crater left by the blast is believed to be more than 300 meters (1,000 feet) wide after it exploded six feet above the ground. Anyone at the blast site was vaporized.

President Donald Trump told reporters at the White House that he was 'very, very proud' and called the operation 'r eally another successful job. We're very, very proud of our military.'

The Pentagon is denying that the attack was a revenge strike despite the fact that it came in the same area of Afghanistan where a Green Beret soldier was killed on Saturday.

Staff Sgt. Mark De Alencar of the 7th Special Forces Group was cut down by enemy small arms fire while his unit was conducting counter-ISIS operations.

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The military used a GBU-43 (pictured), which weighs a staggering 21,600 pounds, and has earned the moniker 'Mother Of All Bombs

That MOAB's first practical test was carried out on March 11, 2003 at Eglin Air Force Base in Florida

HOW THE MOTHER OF ALL BOMBS KILLS PEOPLE: VAPORIZED BODIES, CRUSHED INTERNAL ORGANS AND SUFFOCATED TO DEATH The GBU-43, otherwise known as the Mother of All Bombs, or MOAB unleashes a devastating fireball that incinerates anything within 30 feet when it first detonates. In the milliseconds following the initial blast, all the oxygen would have been sucked out of the tunnels and for hundreds of feet around, literally sucking the life out of terrorists, suffocating them as their lungs imploded. Then, in a flash the fiery shockwave would have blasted outwards at the speed of sound for up to a mile, causing huge concussive injuries to anyone caught in its path, essentially smashing them to death, while at the same time leveling buildings and trees. Ears would have been left bleeding and internal organs battered by the staggering force of the blast. Anyone caught inside the tunnels would have been crushed as the force of 19,000 pounds of highly complex explosives caused them to collapse on the ISIS terrorists. Anyone left alive would have been shocked and left in awe by the ferocity of the blast - the psychological scars staying with them forever. The Pentagon estimates that up to 800 ISIS soldiers were in the area at the time of the blast. Its frightening power was unleashed by the United States for the first time on Thursday when it was dropped on an ISIS camp in Afghanistan's Nangarhar Province, in order to obliterate underground tunnels used by the terrorists. A crater left by the blast is believed to be more than 300 feet wide after it exploded just six feet above the ground. Anyone at the blast site was vaporized. The energy released by the nearly 19,000 pounds of highly complex explosive, would have caused a barometric shock wave known as 'overpressure' that moves at the speed of sound away from ground zero. Classed as a thermobaric bomb - 'thermo' for heat and 'baric' for pressure, the MOAB features a two stage detonation powered by H6 explosive which contains powdered aluminum. The first blast detonates and spreads highly flammable aluminum dust and the second is the baric blast - which literally sucks oxygen out from cave tunnels before rapidly becoming an expanding shock wave. Both the implosion and the blast wave cause massive internal damage to anyone who has not been already been incinerated by the detonation, with most injuries to hollow organs such as the ears, lungs and stomach. Anyone in the tunnels who did not have the life sucked out them would have then been crushed to death by the sheer force of the explosion. MOAB: The Mother of All Bombs - otherwise known as the GBU-43 would obliterate most of Times Square with a yield blast of 0.011 KT Sheer power: The effects of a MOAB detonation are explained below - 1: FireBall - 2 - Air Blast - 3 - Continuing Air Blast and 4 - Burn injuries 1: The MOAB would technically explode as an airburst weapon, albeit from six-feet and not thousands, like a nuclear bomb. 2: As the bomb ignites the alumimum dust and nearly 19,000 pounds of explosives a shock wave sucks the air from another 160-feet of prime Manhattan real estate and destroying Broadway. Concrete buildings are severely damaged and fatalities are also close to 100 percent here. 3: The dissipated air blast continues on to more than 300-feet, damaging more residential buildings and causing injury to anyone caught up in the blast and more fatalities. 4: People up to 330-feet away from Ground Zero would suffer 3rd degree burns and some would suffer the loss of their limbs. Advertisement

President Donald Trump told reporters at the White House that he had authorized his military commanders to take actions like the one put into play on Thursday

Trump suggested he had not personally ordered the bomb strike but delegated authority to commanders in the field.

'Everybody knows exactly what happened. So, what I do is I authorize my military ... We have given them total authorization,' he said.

The move marks the fulfilment of a 17-month-old campaign promise Trump delivered in Iowa, when he scoffed at ISIS terror forces and said he 'would bomb the s**t out of them' if he became president.

It also comes at a moment in the young Trump presidency when tensions are rising with Russia over its role in Syria, where ISIS has its headquarters.

Huge: The MOAB test fired in 2003 shortly before final preparations for it to be loaded onto an MC-130 attack aircraft

Then-candidate Donald Trump told an Iowa audience in November 2015 that he would fight ISIS from the air as president: 'I would bomb the s**t out of them'

The explosion will also send a saber-rattling message to North Korea and Iran that rogue states' nuclear-weapons ambitions could be met with brute force.

Trump said of North Korean dictator Kim Jong-Un: 'I don't know if this sends a message. It doesn't make any difference if it does or not.'

The Department of Defense is denying that Thursday's attack was revenge for Saturday's death of Green Beret sergeant Mark De Alencar in the same region of Afghanistan

'North Korea's a problem. The problem will be taken care of.'

White House press secretary Sean Spicer told reporters that MOAB is 'a large, powerful and accurately delivered weapon' whose use was intended to collapse underground spaces used by ISIS terrorists to move freely and attack U.S. and allied troops.

'The United States takes the fight against ISIS seriously, and in order to defeat the group we must deny them operational space – which we did,' Spicer said.

He referred reporters' questions to the Pentagon and ignored a shouted question about whether Trump had been aware the bomb was dropped before or during the military operation.

Trump said during a November 2015 campaign rally in Fort Dodge, Iowa that ISIS was 'making a tremendous amount of money' because of 'certain areas of oil that they took away' after the Obama administration withdrew U.S. troops from Iraq and Afghanistan.

'They have some in Syria, some in Iraq. I would bomb the s**t out of them,' he said to wild cheers. 'I would just bomb those suckers. That's right. I'd blow up the pipes. ... I'd blow up every single inch. There would be nothing left.'

Preparations: This was the scene as the only other MOAB to be exploded was readied for action in 2003 in Florida. The tail rotor is part of the guidance system for it to exploded over a specified target

Mushroom cloud: This was the aftermath of the test explosion seen outside Eglin Air Force Base in Fort Walton Beach, Florida

The MOAB was pushed out the back door of a giant cargo plane on Thursday, flying to its target with GPS guidance. A MOAB has only been exploded once before - in a 2003 test

ISIS IN AFGHANISTAN ISIS forces operating in Afghanistan have been digging in in Nangarhar province, prompting the U.S. military to drop a 21,000 MOAB ordinance on their underground stronghold. ISIS-K is an ISIS affiliate whose name stands for ISIS Khorosan, operating in Central Asian territory. The group has been using such tactics as improvised explosive devices (IEDs), and tunneling. Recruits from from Pakistan and Central Asia. 'As ISIS-K's losses have mounted, they are using IEDs, bunkers and tunnels to thicken their defense,' said General John W. Nicholson, the U.S. commander in Afghanistan There are between 600 and 800 fighters there, Foreign Policy reported. Afghan forces backed by U.S. forces opened up an offensive against them just last month. 'Our goal is to defeat ISIS-K in Afghanistan in 2017,' Navy Capt. Bill Salvin, a spokesman for the U.S. military command in Kabul, told Foreign Policy. He said the bomb was used against the large tunnel complex because it allowed the fighters 'freedom of movement' to outmaneuver Afghan forces, and while U.S. forces haven't been able to complete their assessment of what the strike might have achieved, 'what we projected is that the bomb has the ability to collapse the tunnels' on top of any fighters inside. U.S. authorities have viewed the group with increasing concern due to its growing strength. Policymakers also fear that ISIS forces may migrate there as allied military campaigns advance on other ISIS strongholds. Advertisement

A specialized MC-130 'Hercules' cargo aircraft released the weapon at 7:00 p.m. local time.

It was too big to drop from a traditional bomb-bay door or release from an aircraft wing, so 'we kicked it out the back door,' a U.S. official told Fox News.

The weapon's sheer power produces a blast that can be felt miles away, largely because of its construction.

Engineers used an unusually thin aluminum skin to encase MOAB's payload, in order to avoid a thicker steel frame interfering with the impact on a target.

The U.S. fast-tracked the MOAB in 2003 for use in Operation Iraqi Freedom, but the Defense Department later decided that the enemy provided too little resistance to justify its deployment.

It was available to the Obama administration throughout the former president's entire two terms, but he never deployed it in combat.

Its first practical test was carried out on March 11, 2003 at Eglin Air Force Base in Florida.

The Pentagon confirmed Thursday that the explosive colossus was dropped in Afghanistan's Nangarhar province, making it the first time America's largest non-nuclear weapon has been used in a combat situation.

Pentagon spokesman Adam Stump said it was the first ever combat use of the bomb, which contains 11 tons of explosives.

Stump said the bomb was dropped on a cave complex believed to be used by ISIS fighters in the Achin district of Nangarhar province, very close to the border with Pakistan.

Gen. John Nicholson, commander of U.S. forces in Afghanistan, said in a statement about ISIS that 'as ISIS-K's losses have mounted, they are using IEDs, bunkers and tunnels to thicken their defense.'

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

News reports suggest Nicholson made the decision to drop it from the sky.

He added that '[t] he 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 ISIS faction in Afghanistan is known as the Islamic State in Iraq and Syria-Khorasan province, or ISIS-K.

HOW 'MOAB' WORKS Key stats: Known as the 'Mother Of All Bombs'

The U.S. military's largest non-nuclear weapon

Each bomb costs around $16 million (£12.8 million)

Its explosion is equivalent to 11 tons of TNT and the blast radius is a mile wide

First tested by US forces in 2003

It is designed to destroy heavily reinforced targets or to shatter ground forces and armour across a large area

30 feet (9 meters) long and 40 inches (1 meter) wide

Weighs 21,000lbs (9,500kg) – heavier than the Hiroshima nuclear bomb

Leaves no lasting radiation effect How it's deployed: The bomb has 'grid' fins that fold into the body and then open up in flight to help control its descent

It can only be deployed out of the back of a large cargo plane due to its size

The bomb rides on a pallet, a parachute pulls the pallet and bomb out of the plane

The pallet then separates so that the bomb can fall to its target

It accelerates rapidly to its terminal velocity and is partially guided to its target via satellite

It explodes six feet (1.8 meters) above the ground

The idea behind this 'airburst' mechanism is to spread its destructive range Advertisement

The weapon carries a blast wave that can be felt more than a mile away