Insurgents Strike Checkpoint in Southern Afghanistan KABUL, Afghanistan - Taliban insurgents wearing police uniforms attacked a checkpoint in southern Afghanistan on Tuesday, killing three police officers, local officials said. NATO confirmed the attack and said fighting was ongoing. The militants" attack on a police checkpoint in the southwest of Kandahar city near a major prison left another seven officers wounded, according to the Kandahar governor's office. Javed Faisal, a spokesman for the governor of Kandahar, said four of the insurgents were killed in the fighting. A police officer who said he was at the fighting said Taliban insurgents first attacked the Afghan police checkpoint and then attacked nearby NATO troops, who returned fire. The police officer did not want to be identified because he was not authorized to speak to the media. A resident of Kandahar, Agha Sardar, said could hear fighting and medical helicopters landing in a nearby area that had been cordoned off by Afghan and NATO troops. NATO and Afghan troops are stationed at the checkpoint. In a separate incident, NATO said that one of its service members was killed on Sunday after three individuals wearing Afghan police uniforms turned their guns on coalition troops, in another apparent "green on blue" attack. The three attackers fled and were being sought, NATO said. Earlier in June, two explosions killed 23 civilians near Kandahar Airfield, one of the largest coalition bases in Afghanistan. Graham Bowley reported from Kabul, Afghanistan, and Taimoor Shah from Kandahar.