As many as 45 civilians have reportedly been killed during a US-led helicopter strike in Helmand province, forcing NATO to launch a probe into the incident.

On Friday, an air strike claimed dozens of lives including children in the Regey village in southern Helmand province, witnesses say.

A BBC journalist visiting Regey village spoke to several people who said they had seen the incident. At the time, dozens were sheltering in the village from nearby fighting.

The report comes amid public outcry over a significant increase in the number of civilian casualties as the result of attacks by the US-led forces in the war-ravaged country of Afghanistan.

International forces in Afghanistan say they are urgently investigating report.

According to several witnesses, clashes in nearby Joshani had forced many civilians to take shelter in the Regey village, while helicopters buzzed over the sky and pounded the village with rockets.

"I heard the sound of the rocket land on our house. I rushed in screaming with my father and saw bodies lying in the dust… I found I was even standing on a dead body," according to a witness who spoke to the BBC journalist.

The incident comes despite earlier promises by the new commander of the US and NATO forces in Afghanistan, General David Petraeus, that protecting civilian lives would top his agenda concerning his war strategies in Afghanistan.

Meanwhile, a spokesman for the NATO, Lieutenant Colonel Chris Hughes said on Sunday that the international forces will probe into the deadly attack.

He said that preliminary investigation by ISAF and the provincial governor "gives no indication of a mass casualty incident cause by the coalition forces in Sangin" in Helmand province.