Thirty-six Islamic State fighters were killed when the US destroyed a militant "sanctuary" in Afghanistan with the so-called Mother Of All Bombs.
The strike on the cave complex in the Achin district of Nangarhar province was the first time the 21,600lb (9,797kg) GBU-43 bomb, which has the explosive power of 11 tons of TNT, has been used in combat.
The Afghan defence ministry said it laid waste to the caves and ammunition caches but had not caused any civilian casualties.
"No civilian has been hurt and only the base which Daesh used to launch attacks in other parts of the province was destroyed," spokesman Dawlat Waziri said.
The bomb, the US military's largest non-nuclear device, was dropped from an MC-130 aircraft very close to the border with Pakistan.
Achin District Governor Esmail Shinwari said: "The explosion was the biggest I have ever seen.
"Towering flames engulfed the area."
The Afghan army spokesman in Nangarhar said the bomb was dropped between two mountains where IS had carved out caves and tunnels.
There were believed to have been between 40 and 70 fighters there at the time, Jawid Saleem told Tolo News.
Residents of the nearby village, which appeared unaffected by the blast, said IS militants could be seen walking up into the mountains every day.
"They were Arabs, Pakistanis, Chinese and local insurgents coming to buy from shops in the bazaar," villager Raz Mohammad told Reuters.
A hospital in the area said it has not received any wounded or dead after the blast.
The nickname - the mother of all bombs - is based on the name given to the weapon by the US Air Force - 'Massive Ordnance Air Blast' bomb and it is regarded as particularly effective against clusters of targets on or just underneath the ground.
The weapon, which was first tested just days before the Iraq War in March 2003, was dropped at 7.32pm local time (4.02pm UK time) after its deployment was signed off by General John Nicholson, the commander of US forces in Afghanistan.
General Nicholson said the strike was designed to minimise the risk to Afghan and US forces conducting clearing operations in the Achin area "while maximising the destruction" of IS fighters and facilities.
However, he insisted there was no wider message in the bomb's use - despite American concerns over North Korea's nuclear threat and anger over Syria's apparent use of chemical weapons.
"It is not related to any outside events other than our focus on destroying Daesh (Islamic State) in 2017," Gen Nicholson said.
Former Afghanistan president Hamid Karzai condemned the use of the MOAB in "strongest words".
"This is not the war on terror but the inhuman and most brutal misuse of our country as testing ground for new and dangerous weapons," he wrote on Twitter.
"It is upon us, Afghans, to stop the USA."
White House press secretary Sean Spicer said of the strike: "The GBU is a large, powerful and accurately delivered weapon.
"We targeted a system of tunnels and caves that ISIS fighters used to move around freely, making it easier for them to target US military advisers and Afghan forces in the area."
An American special forces soldier was killed in the area last Saturday.
The military says it is still assessing the damage it has caused.
US President Donald Trump praised the US military for carrying out another "successful" mission, but was both vague and threatening when asked if the use of the weapon carried an implicit warning to North Korea.
He said: "I don't know if this sends a message to North Korea... North Korea is a problem, the problem will be taken care of."
He then backed China's president Xi Jinping to deal with his ally.