Army and police officers loyal to the Houthi movement shout slogans as they take part in a demonstration to show support to the movement in Sanaa Jan. 23. Yemen drifted deeper into political limbo on Friday after President Abd-Rabbu Mansour Hadi resigned in exasperation at a Houthi rebel takeover of the country, a move that appeared to catch the Iran-backed group off balance. (Khaled Abdullah/Reuters)

Houthi Shiite fighters wearing an army uniform ride on pickup vehicle as they guard a street during a demonstration to show support for their comrades in Sanaa, Yemen, Jan. 23. Thousands of protesters demonstrated Friday across Yemen, some supporting the Shiite rebels who seized the capital and others demanding the country's south secede after the nation's president and Cabinet resigned. (Hani Mohammed/Associated Press)

Followers of the Houthi movement, with portraits of fellow followers who were killed during the recent conflict, demonstrate to show support to the movement in Sanaa Jan. 23 (Khaled Abdullah/Reuters)

Yemeni protesters shout slogans during a rally against the control of capital the by Shiite Huthi rebels on Jan 23, in the capital Sanaa. Yemen faced a dangerous power vacuum after its president announced his resignation over a deadly standoff with Huthi militias controlling the capital and lawmakers called an emergency weekend session. (Mohammed Huwais/AFP/Getty Images)

Houthi Shiite Yemeni carry coffins of fellow men killed during recent clashes with presidential guard forces, during their funeral procession in Sanaa, Yemen, Jan. 23. Shiite rebels have called on supporters to hold mass rallies, a day after the country's embattled president and Cabinet resigned. (Hani Mohammed/Associated Press)

Followers of the Houthi movement demonstrate to show support to the movement in Sanaa Jan. 23. Yemen drifted deeper into political limbo on Friday after President Abd-Rabbu Mansour Hadi resigned in exasperation at a Houthi rebel takeover of the country, a move that appeared to catch the Iran-backed group off balance. Hadi, a former general, blamed the Houthis' control of the capital Sanaa for impeding his attempt to steer Yemen toward stability after years of turmoil and tribal unrest, deepening poverty and U.S. drone strikes on Islamist militants. The banners read: "Allah is the greatest. Death to America, death to Israel, a curse on the Jews, victory to Islam". REUTERS/Khaled Abdullah (YEMEN - Tags: CIVIL UNREST POLITICS) (Khaled Abdullah/Reuters)

Followers of the Houthi movement crowd as they demonstrate to show support to the movement in Sanaa Jan 23. (Khaled Abdullah/Reuters)

A military helicopter hovers above as followers of the Houthi movement as they demonstrate to show support to the movement in Sanaa Jan. 23. (Khaled Abdullah/Reuters)

Houthi Shiite Yemeni wearing army uniforms stand atop an armored vehicle, which was seized from the army during recent clashes, outside the house of Yemen's President Abed Rabbo Mansour Hadi in Sanaa, Yemen, Jan. 22. (Hani Mohammed/Associated Press)

A Yemeni man sits at a market in Sanaa's old city on Jan. 22. Shiite militiamen maintained a tight grip on Yemen's capital with fighters deployed around the presidential palace despite a deal to end what authorities called a coup attempt. (Mohammed Huwais/AFP/Getty Images)

People gather at the site of an explosion in Sanaa Jan. 23. Two improvised explosive devices went off outside houses of Houthi families in Sanaa on Friday, but no casualties were reported, police said. (Khaled Abdullah/REuters)

Tribal gunmen hold weapons apparently to protect their province from possible attacks by Shiite Houthi militias, in the oil-rich province of Marib, Yemen, Jan. 22. Reports state fighting erupted between Shiite Houthi militias and tribal gunmen in the oil-producing province of Marib. (Ali Mohammed/EPA)

Members of the Yemeni presidential guards, wearing civilian clothes, leave the presidential palace with their belongings in Sanaa Jan. 21. Houthi fighters battled guards at the Yemeni president's private home and entered his palace on Tuesday, raising the stakes in a turbulent campaign for more political power that has enfeebled state authority and thrown the Arab state deeper into turmoil. (Khaled Abdullah/Reuters)

Mirrors displayed at a market show the reflections of young Yemenis in Sanaa's old city on Jan. 22. Shiite militiamen maintained a tight grip on Yemen's capital with fighters deployed around the presidential palace. (Mohammed Huwais/AFP/Getty Images)

Houthi Shiite Yemeni gather while guarding a street leading to the presidential palace in Sanaa, Yemen, Jan. 20. Yemen's U.S.-backed leadership came under serious threat as government troops clashed with Shiite rebels near the presidential palace and a key military base in what one official called "a step toward a coup." (Hani Mohammed/Associated Press)

Houthi fighters ride a truck near the presidential palace in Sanaa Jan. 22. Yemen's Houthi rebels welcomed on Thursday proposed concessions by the government on power-sharing but their gunmen still held positions outside the residence of President Abd-Rabbu Mansour Hadi, who remains a virtual prisoner there. (Khaled Abdullah/Reuters)

A Houthi fighter (L) stops a member of the presidential guard wearing civilian clothes from entering the presidential palace in Sanaa Jan. 22. (Khaled Abdullah/Reuters)

Houthi Shiite Yemeni chant slogans during clashes near the presidential palace in Sanaa, Yemen, Jan. 19. Rebel Shiite Houthis battled soldiers near Yemen's presidential palace and elsewhere across the capital, despite a claim of a cease-fire being reached to halt the violence, witnesses and officials said. (Hani Mohammed/Associated Press)