Afghan and US-led forces have inflicted heavy casualties on insurgents in a battle in the eastern province of Nuristan, the Afghan Defence Ministry said on Monday.
The US military and the Defence Ministry said there were no reports of civilian casualties in the battle on Sunday, but a senior provincial official said 22 civilians had been killed.
The fighting erupted during an operation to clear insurgents from villages in the remote province near the Pakistani border and ended when aircraft bombed positions where large numbers of insurgents were fighting, the US military said.
It said several insurgents had been killed in the fighting led by the Afghan army. The Defence Ministry said one Afghan soldier had been killed while the insurgents had suffered heavy casualties.
"There was a great deal of enemy fire being taken. It was a tough fight," said US military spokeswoman Lieutenant-Colonel Rumi Nielson-Green.
The US-led coalition troops called in aircraft which bombed positions that "contained large numbers of heavily armed insurgents", the US military said.
It said villagers in the area lived in fear of insurgents supporting the Hezb-e Islami faction led by former prime minister Gulbuddin Hekmatyar, who is allied with the Taliban and al Qaeda.
Violence has surged in Afghanistan over the past two years. More than 6,000 people were killed last year, almost a third of them civilians.
Rahmatullah Rashidi, the head of Nuristan's provincial council, said Taliban had been in the area but they had fled, and civilians were killed in the bombing.
"More than 20 civilians have been killed and 40 wounded, both men and women," Rashidi told Reuters. "Taliban were there but they had gone by the time the bombing started."
Civilian casualties anger Afghans and are politically damaging for the Western-backed government of President Hamid Karzai. He has repeatedly called on US and Nato-led forces to do everything they can to avoid killing civilians.
The Defence Ministry said it had ordered the Afghan army commander in the area to investigate casualties in the Nuristan battle.
Eight insurgents had been captured and eight government soldiers wounded, the ministry said.
The Taliban and their allies have vowed to step up their violent campaign to expel foreign forces and bring down Karzai's government. (Reuters)
Heavy casualties among insurgents in Afghanistan