Kabul, Afghanistan (CNN) -- Afghan President Hamid Karzai condemned a NATO airstrike this week that a provincial official says killed women and children, in a statement that came just as U.S. Defense Secretary Leon Panetta arrived Thursday in Kabul for talks. A provincial official has said civilians were among the dead in the airstrike, while the NATO-led International Security Assistance Force said initial reports revealed only two injuries. ISAF is aware of the claims of civilian casualties and is looking into what took place, a spokesman for the coalition said. The NATO airstrike Wednesday in eastern Afghanistan's Logar province, along the volatile Pakistan border, is likely to strain already tense relations with the United States.
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NEW: U.N. body says it was the deadliest day for Afghan civilians this year
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U.S. Defense Secretary Leon Panetta meets with Afghan defense minister
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A provincial official says an airstrike in Logar province killed women and children
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ISAF says it is looking into the claims, though its reports show only two injuries
While U.S. military and political officials have said publicly that Afghanistan will be ready to take over security of its country by the time NATO troops depart, critics have said there are questions about whether @placeholder forces can stand on their own.