An Afghan woman was killed and four civilians wounded when a suicide car bomb struck a NATO-led coalition forces' convoy in Kandahar city on Sunday, an official said.The blast occurred around 2 p.m. local time in Police District 5 of Kandahar city, capital of southern province of Kandahar, along a road which connects the city to the international airport, the official, who did not want to be named, told Xinhua news agency."The initial information found a woman was killed and four civilians were wounded by the blast. But no foreigner from the convoy was hurt as they were sitting in bomb proof vehicles," he said."We heard a huge blast when a convoy of international forces was passing our neighbourhood. The whole place has now been sealed off, and no one knows what happened to residents near the blast site," witness Ahmad told Xinhua.Several vehicles and nearby houses were also damaged by the blast, he said.No group has claimed responsibility for the attack, but the Taliban insurgent group routinely claims responsibility for such attacks.More than 2,640 civilians were killed and over 5,370 others injured in conflict-related incidents in first nine months of the year in Afghanistan, according to figures released by the United Nations mission in the country.