'Mother of all bombs' impact in Afghanistan likened to earthquake
The impact of the "mother of all bombs" dropped by US forces in Afghanistan would have been like an earthquake and sends a message about Donald Trump's presidency, experts have said.
The bomb, the largest non-nuclear weapon ever used in combat by the US military, killed 36 Islamic State fighters in a tunnel complex in eastern Afghanistan.
The GBU-43B massive ordnance air blast (MOAB), which contains 11 tonnes of explosives, was used for the first time to destroy IS caves and ammunition caches.
The MOAB, nicknamed the "mother of all bombs", was dropped in the Achin district of Nangarhar province, very close to the border with Pakistan.
US army general John Nicholson, the commander of American forces in the country, said IS - also known as ISIS-K in Afghanistan - were using improvised bombs, bunkers and tunnels to "thicken their defence", so the massive bomb was a necessary response.
"This is the right munition to reduce these obstacles and maintain the momentum of our offensive against ISIS-K," he said.
Former US state department spokesman PJ Crowley told BBC Radio 4's Today programme the use of the weapon was an indication of how Mr Trump had given "greater leeway to the military in terms of what it can do" in Afghanistan and Syria.
Mr Crowley, a former US air force colonel, said the bomb was "like creating a minor earthquake in that particular area".
"It is going to have a profound effect not just in the immediate area, but the concussion extends for a considerable distance," he said.
"It is certainly something that will get the attention of military forces in that area."
He said civilians would have been "impacted in terms of feeling the tremor" of the weapon.
Professor Michael Clarke, a senior associate fellow at defence think tank the Royal United Services Institute, said the use of the weapon would have gone to the White House for approval but was likely to have been a decision made by the local commander.
"It may not have been initiated by President Trump, but nevertheless he is obviously happy to take credit for it and he is happy that it fits into his broader sense that he wants to be militarily credible," he said.
"It is fairly dramatic ... there is a tactical effect on the ground, this is a cave complex the Americans would have known quite a lot about, they knew that if they dropped one of these things it would destroy pretty much everything underground.
"But I think, also, President Trump must have decided: 'Yes, get on and do it, because it is consistent with the message I want to send to the rest of the world.'"
Gen Nicholson said fighters from IS - also known as Daesh - were using tunnels and minefields and the bomb was used to clear those obstacles and destroy their "sanctuary".
"This weapon was very effective in that use, and our soldiers on the ground - our Afghan commandos, our special forces - are on the site now and the weapon achieved its intended purpose," he said at a press conference.
He insisted there was no wider signal being sent by the bomb's use, and it was "simply the appropriate tactical moment against the proper target to use this particular munition".
"It is not related to any outside events other than our focus on destroying Daesh in 2017."
Former Afghan president Hamid Karzai used Twitter to condemn the weapon's use.
"I vehemently and in strongest words condemn the dropping of the latest weapon, the largest non-nuclear bomb, on Afghanistan by US military," he said.
"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."