Foreign and Afghan forces accidentally killed five children in two separate operations Monday, further undermining President Hamid Karzai after he demanded a halt to attacks in civilian areas.

Afghan officials have accused forces from the U.S. and other countries of killing dozens of civilians in recent weeks. The deaths have inflamed tensions across the country and weakened public support for both Karzai''s government and a continued foreign troop presence in Afghanistan.

NATO said it accidentally killed three children in an artillery strike in the east on Monday after insurgents attacked its troops in the area. One artillery round slammed into a house in the Gayan district of Paktika province.

A NATO statement said it "deeply regrets this accident, and an investigation as to the exact circumstances of this tragic event is now under way."

Afghan government officials were not immediately available for comment on Monday, a national holiday.

In a separate raid, police officer Qubaidullah, who like many Afghans goes by one name, said U.S. troops backed by Afghan intelligence agents killed a man and his two children near the capital, Kabul.