Kabul - An Afghan governor said on Monday that more than 20 militants were killed in a US-led operation in eastern Afghanistan, however, a regional lawmaker said that the dead were all civilians, including women and children.

Meanwhile, a Taliban spokesman claimed their fighters had shot down five US military helicopters during the same operation, a claim that the US military spokesperson rejected.

Tamim Nuristani, governor of north-eastern province of Nuristan told Deutsche Presse-Agentur dpa that the operation, which took place in Doaba district of the province on Sunday morning, left more than 20 insurgents killed and scores of them wounded.

The operation, dubbed "Qaher Commando" or "Domandos' anger," was conducted by Afghan and US-led coalition forces, the Afghan defence ministry said in a statement on Monday, adding that three Afghan army soldiers were killed and three others were wounded during the operation.

The statement said that seven militants were arrested in the operation and several others were killed and wounded.

The US military also said on Sunday that their forces killed a "significant" number of insurgents after the rebels attacked a joint Afghan and coalition forces unit during a search operation in the area.

However, Ramatullah Rashed, head of the provincial council told dpa that at least 23 civilians were killed and up to 50 others were injured.

Rashid said that a part of Shorak village, where the operation took place, was completely destroyed in the US military bombardments.

The Afghan army rejected inflicting any civilian casualties in the operation and said that the ministry has set up a commission to conduct an investigation in the area.

Meanwhile Zabihullah Mujahid, a Taliban spokesman, told dpa by phone from an undisclosed location that their "mujahideens" shot downed five US helicopters in Dawaba district

"The helicopters were shot down while they were patrolling in the area," Mujahid said, adding "suddenly Mujahideen fired anti aircraft rockets, and downed the helicopters."

He said that the attack came after the US forces bombarded the area and killed "a number of civilians including women and children."

But, Captain Kymberley Jurado, a US military spokesperson in Bagram, the main US base in Afghanistan rejected the Taliban's claim and said that "no helicopter was shot down during the operation in Nuristan."

Civilian deaths during the international operations have become a sensitive issue for the Western-backed Afghan government. President Hamid Karzai has repeatedly pleaded with foreign forces in the country to avoid causing civilian deaths during their operations.

Karzai believes that civilian losses will erode the public support for his government.

More than 8, 000 people - mostly insurgents but including a quarter of them civilians - were killed in the Taliban-led militancy last year. (dpa)