Islamic State says no fighter killed by mother of all bombs

The Islamic State group has denied suffering any casualties when the US dropped the so-called mother of all bombs in Afghanistan.

The strike on Thursday hit an Islamic State mountain hideout in a remote area of Nangarhar province, in eastern Afghanistan near the Pakistan border.

It was the first time the US military had unleashed the GBU-43/B Massive Ordnance Air Blast bomb, its largest non-nuclear bomb, in combat.

Islamic State issued a statement through its propaganda agency Amaq, saying: "Security source to Amaq agency denies any dead or wounded from yesterday's American strike in Nangarhar using a GBU-43/B."

Afghan officials said the attack left 36 IS fighters dead but caused no civilian casualties.

The top US military commander in Afghanistan said the decision to deploy one of the largest conventional bombs ever used in combat was purely tactical.

"This is the right weapon for the right target," said US General John W. Nicholson, the NATO commander in Afghanistan.

:: Analysis: Trump can't 'flip-flop' on foreign policy forever

The attack, in an area that had seen heavy fighting in recent weeks between Afghan forces and IS militants, destroyed several IS caves and ammunition caches, the Afghan defence ministry said.

A ministry spokesman, General Daulat Waziri, said the bombing was necessary because the tunnel complex was extremely hard to penetrate, with some as deep as 40m.

"It was a strong position and four times we had operations (attacking the site) and it was not possible to advance," he said, adding that the road leading to the complex "was full of mines".

The 21,600lb (9,797kg) GBU-43 bomb, which was dropped from an MC-130 aircraft, has the explosive power of 11 tons of TNT.

The bombing left villagers terrified on both sides of the Afghan-Pakistani border.

In the Afghan village of Achin, just a few miles from where the bomb hit, Palstar Khan said: "Last night's bomb was really huge, when it dropped, everywhere, it was shaking."

Some in Pakistan said the explosion was so loud they thought a bomb had been dropped in their village.

"I was sleeping when we heard a loud explosion. It was an earsplitting blast," said Shah Wali, 46, who lives nine miles from the border.

"I jumped from my bed and came out of my home to see what has gone wrong in our village."