Afghan President Hamid Karzai today told General David Petraeus, the U.S. troop commander in Afghanistan, that civilian casualties caused by U.S.-led forces in his country were "no longer acceptable," and that apologies were "not enough."Karzai's comments follow the deaths of nine children killed March 2 in a NATO helicopter air raid while they were collecting firewood in eastern Kunar Province.Hundreds of people in the Afghan capital, Kabul, gathered today to protest the incident, chanting "Death to America" and carrying posters with images of the children. One protester, Azada, told Reuters that Western powers had overlooked the tragedy."The international community is witness to those killed in the NATO operation, but they are not really paying attention to this," she said. "We want to raise this issue."NATO's International Security Assistance Force has said the children were mistaken for rebels responsible for an earlier attack on a nearby U.S. military base.Civilian casualties have become an increasingly sensitive issue in Afghanistan, where 140,000 U.S.-led troops continue to battle the Taliban and other fighters.Petraeus apologized for the accidental deaths.U.S. President Barack Obama expressed "deep regret" over the incident to Karzai.compiled from agency reports