Four Afghan civilians were killed early Wednesday morning in a bomb explosion in Helmand province, local authorities said. The incident took place in Nawzad district when the vehicle in which the civilians were riding struck a roadside bomb, Afghanistan\'s Khaama Press reported. So far no group has claimed responsibility for the incident, which local officials blame on the Taliban. In a separate incident, five civilians were killed by the Taliban in eastern Kumar province. A provincial security spokesman said the five were abducted by the group before being killed.