Kabul - An Afghan district chief said Monday that a NATO airstrike killed six civilians and wounded more than a dozen others, but the alliance said that "multiple intelligence sources" suggested that four to eight insurgents were killed in the air raid. Zelmai Yousifzai, the district chief of Watapur district in the eastern province of Kunar claimed that six civilians, including two children, one woman and three men, were killed when their house was bombed by an aircraft under NATO command.

Yousifzai said that 14 other civilians were wounded in the raid that took place in the area soon after midnight.

However, the NATO-led International Security Assistance Force (ISAF) claimed in a statement that they had credible intelligence information that four to eight insurgents had assembled in the area in the Watapur valley.

"Intelligence intercepts indicated the hostile intent of the enemy to attack ISAF posts," the statement said, adding, "Due to the remote location, ISAF called in close-air support and eliminated the enemy threat."

"Though the enemy assembly area was remotely located and no apparent civilian structures or personnel were detected prior to the strike, ISAF is investigating the possibility that non-combatants may have been injured."

"We deeply regret any possible civilian injuries caused by our operations against the enemy," Captain Mark Durkin, an ISAF spokesman, said in a statement.

"We will thoroughly investigate the allegations of civilian injuries and, if found true, provide assistance to support the law-abiding people affected," he said.

Civilian casualties have become a delicate issue in Afghanistan. Afghan President Hamid Karzai has repeatedly pleaded with the international forces to avoid civilian killings during their anti-insurgent operations.

Last week five civilians including two women and two children, one of them only seven days old, were killed in a US-led operation in the south-eastern province of Khost. The US military confirmed that civilians were killed in that incident and apologized.

Afghan civilians have borne the brunt of anti-terrorism war in Afghanistan in the past seven years following the fall of the Taliban regime. More than 2,100 civilians were killed in Afghanistan violence last year, according to the United Nations. (dpa)