(Adds suicide bombing) By Zeeshan Haider KABUL, March 14 (Reuters) - A huge blast in an ammunition shop in the heart of the Afghan capital on Wednesday killed at least six people and wounded 10, officials said. A suicide attack killed six more in the country's southeast. Several Kabul shops were razed by the early morning blast. Bystanders tore at rubble with their hands to haul out survivors. "Two of my nephews were killed. We don't know what caused it but it was a loud and terrible explosion," a weeping Haji Qutubuddin said at the scene. "God knows better what was the cause." An Interior Ministry spokesman said at least six people were killed and 10 hurt, and rescuers were combing the site looking for more dead or injured. "The blast occurred in a shop selling gunpowder and other ammunition for hunting rifles," said Ali Shah Paktiawal, Kabul police crime branch chief. In southeastern Afghanistan, meanwhile, two suicide bombers killed six people in the town of Khost in an attack on a senior policeman, a provincial government spokesman said. The officer was wounded. In the southern province of Kandahar, the Taliban heartland, rebels killed at least one policeman in an attack on a patrol. And in the northwestern province of Faryab, suspected Taliban militants riding motorcycles killed a district chief and wounded another in a drive-by shooting. One of the assailants was also killed when guards of the district chief returned the fire while other attackers fled. The Taliban has vowed to step up suicide attacks across the country this year. NATO, meanwhile, has launched a big southern offensive in what analysts say is a crunch year for both sides. Three Taliban suicide bombers killed two people and wounded a dozen on Tuesday in separate attacks in southern Afghanistan. A senior Taliban commander, Mullah Jamaluddin, was killed along with several of his followers in a ground and air strike in Helmand last week, NATO said. (Additional reporting by Saeed Ali Achakzai in SPIN BOLDAK , Tahir Qadiry in MAZAR-E-SHARIF))
