The sky over Sanaa, Yemen, is illuminated by anti-aircraft fire during a Saudi-led airstrike on Friday, April 17. The coalition's warplanes have been carrying out strikes against Houthi rebels since President Abdu Rabu Mansour Hadi fled the country in late March. Shohdi Alsofi/AP
A Yemeni boy holds a rifle as Houthi supporters attend a rally in Sanaa, Yemen, on Sunday, April 5, protesting airstrikes carried out by a Saudi-led coalition against Houthi rebels. YAHYA ARHAB/EPA/LANDOV
Yemenis dig graves on Saturday, April 4, to bury the victims of a reported airstrike by the Saudi-led coalition in the village of Bani Matar, Yemen. MOHAMMED HUWAIS/AFP/Getty Images
Yemenis search for survivors in the rubble of houses destroyed by Saudi-led airstrikes on April 4 in a village near Sanaa. Hani Mohammed/AP
Central Sanaa is covered in dust on Friday, April 3. Airstrikes have turned the bustling capital of Yemen into a ghost town. MOHAMED AL-SAYAGHI/Reuters/LANDOV
A Yemeni man loads a TV set into a van as he prepares to flee Sanaa on Thursday, April 2. Hani Mohammed/AP
Militiamen loyal to Hadi take positions on a street in Aden, Yemen, on Thursday, April 2. Houthi rebels seized the presidential palace in Aden, a neutral security official and two Houthi commanders in Aden told CNN. The Houthis are Shiite Muslims who have long felt marginalized in the majority Sunni country. The Sunni Saudis consider the Houthis proxies for the Shiite government of Iran and fear another Shiite-dominated state in the region. Wael Qubady/AP
A framed photo and a purse hang on the wall of a house destroyed by an airstrike near the Sanaa airport on Tuesday, March 31. KHALED ABDULLAH/Reuters/LANDOV
Buildings burn at the Jabal al-Hadid military camp in Aden on Saturday, March 28. Yemeni military officials said an explosion rocked the camp that houses a weapons depot, killing and wounding several people. The camp reportedly had been taken by security forces loyal to former Yemeni President Ali Abdullah Saleh. Some of the forces aligned with the Houthis are also loyal to Saleh, who resigned in 2012 after months of Arab Spring protests. Yassir Hassan/AP
Yemeni supporters of the Houthi movement attend a demonstration against Saudi military operations Thursday, March 26, in Sanaa. Mohammed Hamoud/Anadolu Agency/Getty Images
People search for survivors under the rubble of houses destroyed by airstrikes near the Sanaa Airport on March 26. Hani Mohammed/AP
Members of Yemen's General People's Committee deploy in Aden, Yemen, on Wednesday, March 25. The militiamen are loyal to Hadi. Wael Shaif Thabet/Anadolu Agency/Getty Images
On March 25, honor guards in Sanaa carry the coffins of victims who were killed in suicide bombing attacks several days earlier. Deadly explosions in Sanaa rocked two mosques serving the Zaidi sect of Shiite Islam, which is followed by the Houthi rebels that took over the capital city in January. Hani Mohammed/AP Yemenis stand in front of burning tires during an anti-Houthi protest in Taiz, Yemen, on Tuesday, March 24. Alaa Amr Al-Ganemi/Anadolu Agency/Getty Images
Medics treat an anti-Houthi protester who was injured during clashes with pro-Houthi police in Taiz on March 24. Anees Mahyoub/AP
Armed men inspect damage after an explosion at the Al Badr mosque in Sanaa on Friday, March 20. MOHAMMED HUWAIS/AFP/Getty Images
A man in Aden holds a police shield that he looted from a base belonging to forces loyal to Saleh on Thursday, March 19. Hamza Hendawi/AP
Houthi supporters in Sanaa deploy giant national flags Wednesday, March 18, during a demonstration to mark the fourth anniversary of the "Friday of Dignity" attack. In 2011, forces loyal to Saleh opened fire on protesters who had gathered in Sanaa to demand the ouster of Saleh and his regime. MOHAMMED HUWAIS/AFP/Getty Images Supporters of Ahmed Ali Abdullah Saleh, the son of the former President, wave banners and shout slogans during a demonstration in Sanaa on Tuesday, March 10. The demonstrators were demanding presidential elections be held and that the younger Saleh run for office. Hani Mohammed/AP
A child raises his fist during a rally by Houthi supporters in Sanaa on Friday, March 6. MOHAMMED HUWAIS/AFP/Getty Images
Thousands of armed Yemeni tribal members gather in the southern province of Shabwa on Monday, February 23. Stringer/AFP/Getty Images
Supporters of the separatist Southern Movement perform prayers during a demonstration in Aden on Friday, February 13. AFP/Getty Images
Houthi fighters guard the gate of the presidential palace where a bomb went off and wounded three people in Sanaa on Saturday, February 7. Hani Ali/Xinhua/SIPA
Yemeni soldiers guard the presidential palace in Sanaa on Friday, February 6. MOHAMMED HUWAIS/AFP/Getty Images
Members of the Houthi movement and their allies attend a meeting in the Yemeni capital on Sunday, February 1. MOHAMMED HUWAIS/AFP/Getty Images
Supporters of the separatist Southern Movement flash the victory sign after they seized police security checkpoints on Saturday, January 24, in Ataq, the capital of the Shabwa province in Yemen. Policemen were told to give up their weapons and return to their bases before the militiamen raised flags of the formerly independent South Yemen at the checkpoints. Stringer/AFP/Getty Images
Houthi rebels fight with Yemeni protesters during a rally in Sanaa on January 24. Thousands of Yemenis took to the streets of Sanaa in the largest demonstration against Houthis since the Shiite militiamen overran the capital in September. MOHAMMED HUWAIS/AFP/Getty Images
On Friday, January 23, Houthis carry coffins of those killed during recent clashes with presidential guard forces in Sanaa. Hani Mohammed/AP
A Houthi militiaman sits near a tank near the presidential palace in Sanaa on Thursday, January 22. MOHAMMED HUWAIS/AFP/Getty Images
Houthi men wearing army uniforms stand guard on a street leading to the presidential palace in Sanaa on Wednesday, January 21. Hani Mohammed/AP
A wounded man rests at a hospital in Sanaa on January 21. He was reportedly injured in fierce clashes the previous day. MOHAMMED HUWAIS/AFP/Getty Images
A tank is stationed in front of the Sanaa house of President Abdu Rabu Mansour Hadi on January 21. ABDULRAHMAN HWAIS/EPA/LANDOV
A Houthi rebel mans a checkpoint near the presidential palace on January 21. MOHAMMED HUWAIS/AFP/Getty Images
A man walks inside a heavily damaged house near the presidential palace on Tuesday, January 20. MOHAMMED HUWAIS/AFP/Getty Images
A woman walks past closed shops in Sanaa on January 20. MOHAMMED HUWAIS/AFP/Getty Images
An armed member of the Houthi movement stands guard in the streets of Sanaa on January 20. GAMAL NOMAN/AFP/Getty Images
A man surveys his damaged home in Sanaa on January 20. MOHAMMED HUWAIS/AFP/Getty Images
Houthis inspect a damaged mosque in Sanaa on January 20. MOHAMMED HUWAIS/AFP/Getty Images
Houthi men raise their weapons during clashes near the presidential palace on Monday, January 19. Hani Mohammed/AP
Smoke and flames rise in Sanaa during heavy clashes between presidential guards and Houthi rebels on January 19. Stringer/EPA/Landov
Tribal soldiers protecting the city from Houthi rebels stand guard at the city borders in Marib, Yemen, on January 19. Ali Owimdha/Anadolu Agency/Getty Images
Houthi men guard a Sanaa street on January 19. Hani Mohammed/AP