KANDAHAR, Afghanistan (Reuters) - The U.S. military says it is investigating an incident in southern Afghanistan in which residents said some civilians were killed and up to 16 wounded in a possible air strike.
Civilian casualties, often caused by air strikes, have been a source of great tension between U.S. and NATO-led troops, prompting the commander of foreign forces to issue new combat orders designed to reduce such incidents.
The issue has led to a rift between President Hamid Karzai's government and its Western backers, with Karzai saying foreign air strikes have accomplished nothing but the deaths of civilians.
The latest apparent incident happened overnight on July 16 in southern Kandahar Province, the birthplace of the Taliban which remains an insurgent stronghold.
"We are aware an event happened in Kandahar. We have forces down there and they were engaged but I don't know the specifics," said Captain Elizabeth Mathias, a U.S. military spokeswoman in Kabul.
Residents said up to six people were killed and 16 wounded in two Kandahar districts they identified as Shah Wali Kot and Miawand.
"I was at home last night when our house was bombed," a Shah Wali Kot resident who identified himself as Mohammadullah told Reuters television.
He said 12 of his family members were wounded and that a four-year-old girl was among four people killed.
District officials who asked not to be identified said another two people were killed and four wounded in Miawand in attacks they said involved helicopters.
Television footage taken inside Kandahar City hospital showed a number of wounded, including children, being treated.
General Stanley McChrystal, who took charge of foreign troops in Afghanistan last month, has said international forces need to make a "cultural shift" away from conventional warfare and focus on winning the support of Afghan troops.
His comments came as 4,000 U.S. Marines this month launched the biggest operation of the eight-year-old war in Helmand, next to Kandahar, another Taliban stronghold which produces most of the opium poppy that helps fund the insurgency.
That assault, Operation Strike of the Sword, was the first major offensive under U.S. President Barack Obama's new regional strategy to defeat the Taliban and stabilize Afghanistan.
McChrystal's comments, and the new tactical directive, followed an incident in western Farah Province in May in which dozens of civilians were killed in air strikes, leaving many Afghans seething with anger.
Karzai later called for an end to such strikes. A U.S. military report has since found that strikes by U.S. B1 bombers in Farah violated orders already in place at the time. That report recommended ordering all U.S. forces operating in Afghanistan undergo new training.
The new directive calls for military commanders to "scrutinize" and "limit" the use of close air support against residential compounds and other areas likely to result in civilian casualties.
Some 800 civilians were killed in Afghanistan between January and May this year, a 24 percent increase from the same period in 2008, according to UN figures released last month.
More than half of those deaths were caused by insurgents and just over a third by international and Afghan forces, the United Nations said. The rest could not be attributed to either side.