A policeman (L) and air force officers gather at the site of a bomb attack on a military bus in Sanaa August 25, 2013. At least six people were killed and 26 wounded on Sunday in the bomb attack on the bus carrying members of Yemen’s air force to their base in the capital Sanaa, witnesses and medics said. REUTERS/Khaled Abdullah (YEMEN – Tags: CRIME LAW MILITARY TPX IMAGES OF THE DAY)