A car bomb detonated Sunday in the southern Afghanistan city of Kandahar, killing seven people and injuring 19 others, police said. The blast happened outside a police station around noon and was followed by 10 minutes of gunfire, Khaama Press reported. Among the dead were five Afghan police officers. Another six officers were injured, the report said. There was no immediate claim of responsibility for the attack, but a spokesman for provincial Gov. Sayed Anwar Rahmati said it had the hallmark of the Taliban fundamentalist group, The Washington Post said. The governor\'s office also announced Sunday a U.S. soldier had mistakenly shot and killed an Afghan guard at the U.S. military base in Sar-i-Pul in northern Afghanistan Friday night. The U.S. soldier opened a door and saw a gun barrel and in a \"mistaken act,\" opened fire, the governor told the Post. NATO officials said an investigation was under way, but offered no further details.