A Houthi follower holds up his rifle during a demonstration against the Saudi-led air strikes, in Sanaa May 8, 2015. Saudi-led forces carried out air strikes on Friday in Yemen's Saada province, a bastion of Iranian-allied Houthi rebels, and warned all civilians to leave a day after Riyadh promised a harsh response to cross-border Houthi attacks. REUTERS/Khaled Abdullah TPX IMAGES OF THE DAY