SEATTLE - A US soldier accused of killing 16 villagers in Afghanistan is due to be arraigned on Thursday on charges of premeditated murder, for which military prosecutors are seeking the death penalty.Robert Bales, a veteran of four combat tours in Iraq and Afghanistan, is accused of gunning down the villagers - mostly women and children - in their homes in two villages in Afghanistan's Kandahar province.The shootings occurred over a five-hour period in March. It was one of the deadliest incidents the military has blamed on a rogue US soldier since the Vietnam War and strained US-Afghan relations.