An Afghan boy cries after his parents were allegedly killed during a raid in Bati Kot area of Nangarhar province, in Afghanistan, 29 Apr 2007

U.S. officials say they launched the raid early Sunday after receiving a tip that militants in the eastern province of Nangarhar were planning a series of suicide attacks in the next few weeks.

Major William Mitchell says the U.S.-led coalition and Afghan forces came under attack as they approached the militants' compound and returned fire, killing four militants.

"Unfortunately an adult woman and a teenager were also killed in the crossfire between militants and Coalition forces," he said. "A young child and a teenage female were wounded during the firefight and are being treated at a Coalition medical facility."

He says coalition forces found multiple AK-47 machine guns and bomb-making materials inside.

U.S. officials also released a written statement expressing concern over the loss of civilian lives. They accused the militants of endangering innocents by hiding among their families.

The incident provoked a massive protest in the area. Hundreds of local men chanted "death to Bush" and temporarily blocked the region's main highway.

This is the second time in recent weeks that U.S. led forces are being blamed for civilian casualties in Nangarhar, one of the key battleground states in the fight against the five year old Taleban insurgency.

On March 4, U.S. Marines killed 12 people after being attacked by a suicide car bomber.

Local eyewitnesses say the American forces fired indiscriminately into groups of Afghan cars and pedestrians as they tried to escape the ambush.

The U.S. military subsequently determined the Marines used excessive force in the incident and the Afghan Independent Human Rights Commission recently accused the Marines of violating international humanitarian law.

Afghan President Hamid Karzai has repeatedly denounced U.S. and coalition military action that harms civilians, which is a major point of concern for Afghans following more than three decades of foreign invasion and civil unrest.