KABUL (Reuters) - Two patients and a caretaker were killed during an overnight raid by Afghan forces on a health clinic in the central province of Wardak, the Swedish Committee for Afghanistan, the aid group which runs the facility, said on Thursday.The aid group said the information it had received indicated the Afghan National Army had conducted the raid on the clinic in the Tangi Saidan area of Wardak late on Wednesday night and it called for those responsible to be held accountable."This attack constitutes a gross violation of humanitarian principles and the Geneva Convention that all actors of a conflict have to respect," said Jorgen Holmstrom, Country Director of SCA, in a statement."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.Provincial government spokesman Hemat, who like many Afghans goes by one name only, said a special forces unit conducted an operation in the Tangi Saidan area of Wardak and killed four insurgents. He said he was unaware of a raid on a hospital.A spokesman for the Afghan defense ministry said he had no information on any operation in the area. An interior ministry spokesman said an operation against Taliban members had been conducted in Wardak but had not targeted a hospital.In a statement, the Taliban said the attack was carried out by U.S.-led troops but a spokesman at the headquarters of NATO's Resolute Support mission in Kabul said there was no indication of any operations by international forces in the area."At this time we have no operational reporting of any coalition or U.S.activity in the vicinity of any hospitals in Wardak," said Resolute Support public affairs director, U.S. Army Col. Michael Lawhorn.The incident comes less than five months after 42 people were killed in a U.S. air strike on a hospital in the northern city of Kunduz run by medical aid group Medicins Sans Frontieres.A report from the United Nations this week said that civilian casualties rose to 11,000 last year, around 17 percent of which were caused by forces on the government side.(Reporting by James Mackenzie and Hamid Shalizi and Mustafa Andalib in Ghazni; Editing by Simon Cameron-Moore)Join the conversation about this story Click here to read full news..