Tribesman loyal to Yemeni opposition tribal chief Sheikh Sadiq al-Ahmar guards during the visit of United Nations human rights investigators to al-Ahmar destroyed house in Sanaa June 29, 2011. A team of United Nations human rights investigators arrived in Yemen on Tuesday to assess the situation in the country after months of unrest. REUTERS/Suhaib Salem (YEMEN - Tags: POLITICS CIVIL UNREST IMAGES OF THE DAY)