‘Death to America' chants KANDAHAR – International troops opened fire on a bus carrying Afghan civilians Monday, killing four people and wounding 18, an Afghan official Zelmai Ayubi said, setting off anti-American protests in a key southern city where coalition forces hope to rally the public for a coming offensive against the Taliban. He said international forces took 12 of the wounded to a military hospital. NATO said it was investigating the shooting. A passenger interviewed at Kandahar hospital, Rozi Mohammad, said they had just left the Kandahar terminal when the bus pulled over to allow an American convoy to pass. Shooting broke out as the third or fourth American vehicle went by, he said, with gunfire coming from the direction of the convoy. “They just suddenly opened fire, I don't know why. We had been stopped and after that I don't know what happened,” said Mohammad, his left eye was swollen shut and his beard and clothing matted with blood. Doctors said he had suffered a head injury but did not yet know how serious it was. Within hours, scores of Afghans had blocked the main highway out of Kandahar city with burning tires, chanting “Death to America,” and calling for the downfall of Afghan President Hamid Karzai, himself a Kandahar native. “The Americans are constantly killing our civilians and the government is not demanding an explanation,” said resident Mohammad Razaq. “We demand justice from the Karzai government and the punishment of those soldiers responsible.” NATO and Afghan authorities declined to identify the international forces involved by nationality, although numerous eyewitnesses said they were American. Karzai issued a statement condemning the attack and expressing condolences to the victims.