A man walks atop rubble of buildings damaged by what activists said was shelling by forces loyal to Syria's President Bashar al-Assad in the old city of Homs March 26, 2013. Picture taken March 26, 2013. REUTERS/Mohamed Ibrahim/Shaam News Network/Handout (SYRIA - Tags: CONFLICT) ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS