A Palestinian tries to kick a tear gas canister fired by Israeli security forces during clashes at a protest in the mostly Arab neighborhood of Silwan in East Jerusalem May 13, 2011. [Photo/Agencies]

Supporters of Yemen's President Ali Abdullah Saleh climb a billboard frame during a rally in Sanaa May 13, 2011. Huge crowds in Sanaa and other Yemeni cities demanded on Friday that Saleh leave after months of popular tumult that has brought the country close to economic meltdown. [Photo/Agencies]