Female demonstrators hold up posters of Yemen's president during an August pro-government demonstration in Sanaa. The rebels took over the presidential palace on Tuesday. Mohammed Huwais/AFP/Getty Images hide caption

itoggle caption Mohammed Huwais/AFP/Getty Images

Houses of local residents are seen damaged in clashes that erupted between presidential guards and Shiite Houthi fighters in Sanaa, Yemen, on Tuesday. Hani Ali/Xinhua/Landov hide caption

itoggle caption Hani Ali/Xinhua/Landov

South African Pierre Korkie was killed in a failed rescue attempt along with American photojournalist Luke Somers. U.S. officials were reportedly unaware that Korkie was being held along with Somers nor that arrangements had already been made for his release. AP hide caption

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Luke Somers, 33, an American photojournalist who was kidnapped over a year ago by al-Qaida, poses for a picture during a parade marking the second anniversary of the revolution in Sanaa, Yemen. Hani Mohammed/AP hide caption

itoggle caption Hani Mohammed/AP

Yemeni soldiers hold up their weapons at an area seized from al-Qaida in the southeastern province of Shabwa, Yemen, on May 8. President Obama said Wednesday that U.S. strategy against the so-called Islamic State would be similar to how it targeted militants in Yemen and Somalia. Yemen's Defense Ministry/AP hide caption

itoggle caption Yemen's Defense Ministry/AP

Smoke rises from the site of a suicide car bombing at the Defense Ministry in Sanaa, the Yemeni capital, Thursday. Mohammed Huwais/AFP/Getty Images hide caption

itoggle caption Mohammed Huwais/AFP/Getty Images

A Yemeni soldier searches a car near the airport in the capital, Sanaa. The United States has ordered Americans to leave Yemen immediately amid a warning of a possible attack. Mohammed Huwais/AFP/Getty Images hide caption

itoggle caption Mohammed Huwais/AFP/Getty Images

A Yemeni soldier stands guard Tuesday near Sanaa International Airport. Mohammed Huwais /AFP/Getty Images hide caption

itoggle caption Mohammed Huwais /AFP/Getty Images

An army trooper sits beside a machine gun that is mounted on a patrol vehicle at a checkpoint in Sanaa, Yemen. Security is tight in the capital amid warnings about possible terrorist attacks. Khaled Abdullah /Reuters /Landov hide caption

itoggle caption Khaled Abdullah /Reuters /Landov

John Brennan, President Obama's nominee to be the next CIA director, worked closely with Saudi Arabia to set up a secret U.S. drone base there, The New York Times reported. Brennan's confirmation hearing is Thursday. Kevin Dietsch /UPI /Landov hide caption

itoggle caption Kevin Dietsch /UPI /Landov

Security guards were deployed outside the graffiti-covered walls of the U.S. Embassy in Cairo, Egypt, which came under attack Tuesday. Mohamed Abd El Ghany/Reuters/Landov hide caption

itoggle caption Mohamed Abd El Ghany/Reuters/Landov

This 2010 image, provided by IntelCenter, shows Humam Khalil Abu-Mulal al-Balawi in a posthumous video message posted on extremist websites. The al-Qaida double agent killed seven CIA operatives, a Jordanian spy and himself when he set off a bomb strapped to his body at a base in Afghanistan in December 2009. AP/IntelCenter hide caption

itoggle caption AP/IntelCenter