The US-led troops called in gunship helicopters Monday afternoon to retaliate on militants who earlier that day attacked them at Wech Baghtu village in Shah Wali Kot district of Kandahar. However, the air bombing hit a wedding party being held near the hilly area where the Taliban insurgents' firing came from, according to locals.

Condemning the incident, Afghan President Hamid Karzai was saddened by "the killing of 40 civilians and injuring of 28 others in a Coalition air strike," a statement from his office said. "President Karzai has stressed repeatedly in the past that civilian casualties should be avoided but the Coalition forces usually carry out bombing without planning."

Haji Roozi Khan, owner of the house where the wedding ceremony was held, earlier told Xinhua that at least 37 civilians including10 women, 23 children were killed and 35 others including the bride wounded in the bombing and firing of Coalition forces which lasted from 2 pm Monday until late that night.

A Xinhua reporter at the scene yesterday afternoon saw many locals there were still searching the debris for their relatives' dead bodies. Locals said the casualties' figure was expected to rise.

The Afghanistan-based US forces said it had initiated an investigation and dispatched coalition personnel to the site.

"Though facts are unclear at this point, we take very seriously our responsibility to protect the people of Afghanistan and to avoid circumstances where noncombatant civilians are placed at risk," said a US military statement.

While congratulating Barack Obama on his victory in Tuesday's US presidential elections, Afghan President Hamid Karzai called on the new leadership of the US at a press conference earlier yesterday to prevent from harming civilians in their military operations in Afghanistan, where some 70,000 US and NATO troops are fighting Taliban and al-Qaeda militants.

"Our first demand is to avoid harming civilians in Afghanistan," Karzai said.

Civilian killings are sensitive and continuous happenings in the past years have spurred common Afghans' anger, if not hatred, towards US-led foreign troops and undermined the popularity of the Western-backed Karzai administration.

A bloodiest one in years was on August 22 when a US airstrike in Shindand district of western Herat province, according to the UN and Afghan government probe, claimed over 90 civilian lives, which prompted the Afghan cabinet to pass a historic resolution asking for a re-regulation of foreign troops' presence in the post-Taliban nation.

Though the Afghan authorities repeatedly ask for better coordinated operations of foreign troops and an end to civilian casualties, the Western troops, mostly relying on air bombing to fight insurgents, continue to pound civilian targets, either due to misleading information, aimless firing, or self-protection in cases of so-called "escalation of force."

In several reported cases, the result of the probe done by the foreign troops usually came late and the figure of civilian deaths they confirmed was much smaller than reported from locals.

Obama, the new US president-elect, has said before that he, if got elected, will send 7,000 more troops to the Afghan battlefield. He also threatened to launch uni-lateral attacks across the Afghan border, conditionally if Pakistan is "unable" or "unwilling" to contain the reported escalating cross-border militant violence.

Karzai in his yesterday talk also demanded from the US a change of its Afghan war strategy, saying, "The war on terror should be conducted in areas where the sanctuaries of terrorists and their training centers exist."

The Afghan leader is apparently referring to the reported militant hideouts in neighbouring Pakistan's northwestern tribal areas, which he has emphasized must be dismantled for ending insurgency inside his own country.

The US forces in Afghanistan had conducted several bombing attacks into Pakistani side which was said to target militants but sometimes killed civilians. Islamabad categorically condemned the uni-lateral cross-border attacks, saying it has the capability to handle militants on its sovereign soil.