Civilian deaths and intrusive searches have bred resentment among the Afghan population nearly eight years after the U.S.-led coalition invaded to oust the Taliban's hard-line Islamist regime for sheltering al-Qaida terrorist leaders.
Foreign forces are working to persuade the population to support the Afghan government after last month's presidential election, which has yet to be decided amid allegations of vote-rigging.
On Monday, the Swedish Committee for Afghanistan said the U.S. Army's 10th Mountain Division forced their way into the charity's hospital without permission to look for insurgents in Wardak province, southwest of Kabul.
"This is a clear violation of internationally recognized rules and principles," said Anders Fange, the charity's country director. He said it also went against an agreement between NATO forces and charities working in the area.
The U.S. troops came to the hospital looking for Taliban insurgents late at night last Wednesday. Fange said they kicked in doors, tied up four hospital guards and two people visiting hospitalized relatives, and forced patients out of beds during their search.
They also barged into women's wards, he said, adding that strange men entering rooms where women are in beds is a serious insult to the local Pashtun culture and word of it could turn the community against international troops.
When they left two hours later, the soldiers ordered hospital staff to inform coalition forces if any wounded insurgents were admitted, and the military would decide if they could be treated, he said.
The staff refused. Fange said informing on patients would put the staff at risk and make the hospital a target and he demanded guarantees the military would not enter hospitals without permission in future.
"If the international military forces are not respecting the sanctity of health facilities, then there is no reason for the Taliban to do it either," he said. "Then these clinics and hospitals would become military targets."
U.S. military spokeswoman Lt. Cmdr. Christine Sidenstricker confirmed that the hospital was searched last week but had no other details. She said the military was looking into the incident.
"We are investigating and we take allegations like this seriously," she said. "Complaints like this are rare."
Violence has surged across much of Afghanistan since President Barack Obama ordered 21,000 more U.S. troops to the country this year. Two foreign troops were killed Sunday when their patrol hit a roadside bomb and a third died of wounded sustained in a separate gunbattle with insurgents, NATO said without giving their nationalities. All three deaths were in volatile southern Afghanistan.
NATO was also investigating last week's U.S. airstrike. The strike came despite new rules for foreign forces limiting use of airpower to avoid civilian casualties.
The provincial government said most of the dead were militants, but on Monday, the Afghan Rights Monitor said interviews with 15 villagers indicate that only a dozen gunmen died and 60-70 villagers were killed. The group called for further investigations.
"Even if all the victims were supporters of the Taliban, the fact that most of them were unarmed and were not engaged in any combat activity does not warrant their mass killing," said Ajmal Samadi, the rights group's director.
A spokesman for the provincial government, Ahmad Sami Yawar, said Monday that only five of the estimated 70 killed were civilians.
Meanwhile, insurgents killed more civilians in bombings and other attacks. On Monday, the government said three militant rockets landed overnight in the capital, Kabul, hitting a house and killing three people. In central Uruzgan province, a remote-controlled bomb targeting a police vehicle exploded in a busy market, killing two children and wounding 16 other people, according to local police official Gulab Khan.
A United Nations report in July said the number of civilians killed in conflict in Afghanistan has jumped 24 percent this year, with bombings by insurgents and airstrikes by international forces the biggest killers. The report said 1,013 civilians were killed in the first half of 2009, 59 percent in insurgent attacks and 30.5 percent by foreign and Afghan government forces. The rest were undetermined.
Associated Press Writer Rahim Faiez in Kabul contributed to this report.