TAIZ, 13 Dec -- A soldier Sunday emptied the clip of his semi-automatic rifle at a crowd of fellow soldiers killing seven and wounding six others.  The soldier, Mansour Ali al-Dais was recently assigned to guard the National Museum in the southern city of Taiz amid reports he was suffering from psychological problems.  Other reports said he spent seven months in prison for tossing a hand grenade at a crowd wounding 10 last year.  The Islamist Alsahwa website cited local sources in Taiz as saying “six soldier were killed in the shootout and 11 others including four civilians were injured,” adding “the soldier opened fire at fellow soldiers inside the museum.”  He was later arrested after he fortified for hours inside the museum and is being questioned.