Afghan and U.S. flags fly side by side during a security handover ceremony in Panjshir province in 2011. U.S. officials are looking into allegations that U.S. troops may have been involved in a deadly raid on a clinic in Wardak province Wednesday night. (Ahmad Masood/Reuters)

Afghan security forces raided a charitable health clinic in Wardak province Wednesday night, killing two patients and a caretaker in another incident billed as a potential war crime here, according to the human rights organization that operates the clinic.

The Swedish Committee for Afghanistan said in a statement that the Afghan National Army had conducted the raid, calling the attack “a gross violation of humanitarian principles and the Geneva Convention.”

Bjorn Lindh, a spokesman for the group, said Afghan troops arrived near the 10-bed clinic in a helicopter about 11 p.m. Initially, he said, they went to the home of a local ambulance driver and detained him. The ambulance driver then escorted the soldiers to the health clinic.

[U.N.: 2015 civilian injuries in Afghan war worst since 2009]

The troops stormed into the clinic and began arresting and beating staff members, Lindh said, adding that they then “found two patients who were injured in some way.”

“They took these people out of the clinic to a nearby bazaar and killed them,” Lindh said. A 15-year-old boy who had been watching over the two men was also killed, he said.

A spokesman for the Defense Ministry did not return several calls for comment.

Some local officials in Wardak, south of Kabul, alleged that U.S. forces were also involved in the raid, perhaps flying the helicopters that transported Afghan security personnel to the area.

Col. Michael T. Lawhorn, spokesman for the U.S.-led coalition, said officials are investigating those claims.

“We are aware of those reports, and we are looking into them,” Lawhorn said.

Gen. Razeq Safi, commander of an Afghan army brigade for Logar and Wardak provinces, said that four Taliban insurgents were killed and two others wounded during the incident. Another insurgent was also taken in custody, he said.

But Safi denied that the Afghan army had conducted the raid, saying he suspects Afghan police special forces carried it out in cooperation with “foreign troops.”

“Choppers were seen last night,” Safi said. “Airstrikes have also taken place there.”

An official with the Afghan Interior Ministry, which oversees the police, said the agency did conduct operations in Wardak on Wednesday night but declined to comment on whether they took place near the health clinic.

The apparent raid comes less than six months after U.S. Special Forces mistakenly strafed a Doctors Without Borders hospital in Kunduz in northern Afghanistan, killing at least 42 patients, medical staffers and caretakers. President Obama apologized for that airstrike, but Doctors Without Borders is pressing for war crimes charges to be filed.

Gen. John Campbell, the outgoing commander of U.S. forces in Afghanistan, blamed “human error” for the Kunduz strike. Campbell said U.S. Special Forces who had been operating in that area had not been briefed that the Doctors Without Borders compound was a hospital.

Afghan security forces, however, have been known to routinely enter medical facilities in pursuit of militants, even though hospitals are considered neutral spaces under international law. A few months before the hospital in Kunduz was bombed, Doctors Without Borders complained that Afghan troops had illegally entered the facility.

[What exactly happened in Kunduz is still unclear]

A report released Sunday by the U.N. Assistance Mission in Afghanistan noted that coalition and Afghan special forces raided health facilities in Logar and Helmand provinces in December. The report said the search operations “resulted in the arrest of healthcare staff and destruction of clinic equipment — although they did not cause any civilian casualties.”

Jorgen Holmstrom, the country director for the Swedish Committee for Afghanistan, said all the patients in the group’s clinics had the right to be protected.

“Medical facilities and medical staff are to provide treatment to anyone in need, and patients are to be granted safety according to humanitarian law,” he said.

Lindh noted that the Swedish Committee for Afghanistan is the only medical provider in Wardak province, where fierce battles between Afghan security forces and Taliban militants are common.

Abdul Wali Noorzai, a spokesman for the provincial police force, said the raid began when Afghan special forces used ropes to descend into the village from a helicopter.

“The operation was conducted at night, and Afghans do not have the technology to do it by air, lowering troops onto the ground,” he said. “I think Americans were present with them.”

U.S. military officials say the Afghan army sometimes uses its own helicopters now to conduct night operations, without the presence of coalition advisers.

Hameeda Akbari, a member of parliament from the area, said the hospital was well-known for treating Taliban militants. She called the raid “justifiable.”

“That hospital treats the opposition,” Akbari said.

But Lindh stressed that the staff at the health clinic “is not part of this conflict.”

“Anyone who comes to our clinics, we don’t ask questions, and they should feel protected,” Lindh said. “But they were taken out, and they were killed.”

Mohammad Sharif in Kabul and Dan Lamothe in Washington contributed to this report.

Read more:

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U.S. airstrikes in Kunduz destroyed more than a hospital

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