US troops are still battling suspected Islamic State fighters near the site where a massive bomb was dropped in eastern Afghanistan last week, a US military official say.
Nicknamed "the mother of all bombs", the GBU-43 Massive Ordnance Air Blast bomb was dropped last Thursday from an American MC-130 aircraft in the Achin district of Nangarhar, bordering Pakistan.
Since then questions have surrounded the decision to use the weapon, which is one of the largest conventional bombs ever used in combat by the US military. The strike drew condemnation from some prominent figures, including former Afghan president Hamid Karzai and Afghanistan's ambassador to Pakistan.
After arriving at the site the day after the strike, US troops, who are fighting alongside Afghan forces, have since left but continue to conduct operations in the area, said US military spokesman Captain William Salvin.
"Access has been restricted but that's because it's a combat zone," he told Reuters. "We are in contact with the enemy."
Echoing initial estimates, Capt Salvin said the US military has "high confidence" that no civilians were harmed, although no independent investigators have been able to visit the site.
Some Afghan officials have complained of a lack of information about the effects of the bomb.
In meetings of the Afghan security council, some ministers told President Ashraf Ghani they feared the dearth of information from the US side could be exploited by Islamic State, which has continued radio broadcasts claiming that none of its fighters were killed.
Capt Salvin would not comment on claims by Afghan defence officials that nearly 100 Islamic State fighters died in the strike.
The attack was aimed at destroying an "extensive" complex of fortified tunnels and mines and not any particularly large concentration of fighters, he said.