US strike kills 18, including Afghan civilians: Officials

Kabul: Civilians were among at least 18 people killed in a US air strike against Islamic State militants in eastern Afghanistan on Wednesday, officials said, with conflicting claims about the number of civilian deaths.

The attack happened in Achin district, a hotbed of IS insurgents in Nangarhar province near the border with Pakistan, as local residents gathered to welcome a tribal elder who had recently returned from the hajj pilgrimage.

"Three civilians lost their lives in this strike," Achin police chief Mohammad Ali told AFP, adding that 15 militants were also killed.

But Esmatullah Shinwari, a Nangarhar MP, said the strike killed 13 civilian relatives of the local elder. Six IS fighters were also killed, he added.

The American military said it conducted a "counter-terrorism airstrike in Achin" on Wednesday, adding it was aware of claims of civilian casualties.

"We... are currently reviewing all materials related to this strike," US military spokesman Charles Cleveland said in a statement.

"US Forces-Afghanistan takes all allegations of civilian casualties very seriously."

There was no information on whether it was an attack by a drone or a piloted aircraft.

Islamic State first emerged in Afghanistan in late 2014 and has since violently challenged the much larger Afghan Taliban movement in parts of the country`s east.

But the fighters have steadily lost territory in recent months because of stepped-up US airstrikes and a ground campaign by Afghan forces in Nangarhar.

They are confined to two or three districts including Achin, according to Afghan and US officials.

Civilian and military casualties caused by NATO forces have been one of the most contentious issues in the 15-year campaign against the insurgents, prompting harsh public and government criticism.

A US air strike killed eight Afghan policemen earlier this month in the southern province of Uruzgan in the first apparent "friendly fire" incident since American forces were given greater powers to strike at insurgents in June.

The new authority gave the US-led NATO troops greater latitude to order air strikes in support of Afghan troops.