(01 of29)
Open Image ModalThis picture taken on Wednesday, March 5, 2014, provided by the anti-government activist group Aleppo Media Center, which has been authenticated based on its contents and other AP reporting, shows Syrians inspecting the rubble of a destroyed buildings following a Syrian government airstrike in Aleppo, Syria. (AP Photo/Aleppo Media Center AMC) (credit:AP)
(02 of29)
Open Image ModalThis picture taken on Saturday, March 1, 2014, provided by the anti-government activist group Coordination Committee In Kfar Takharim, which has been authenticated based on its contents and other AP reporting, shows Syrian citizens trying to extinguish flames rising from buildings that were attacked by Syrian government airstrike in the town of Kfar Takharim in the northwest province of Idlib, Syria. (AP Photo/Coordination Committee In Kfar Takharim) (credit:AP)
(03 of29)
Open Image ModalA picture shows Syria's empty chair at an Arab foreign ministers meeting in the Egyptian capital of Cairo on March 9, 2014. (KHALED DESOUKI/AFP/Getty Images) (credit:Getty Images)
(04 of29)
Open Image ModalA man is comforted by a rescue worker and others following a reported air strike by government forces in which a fellow rescue worker was killed on March 9, 2014 in the northern city of Aleppo. (Fadi al-Halabi/AFP/Getty Images) (credit:Getty Images)
(05 of29)
Open Image ModalAn injured Syrian rescue worker reacts as he receives medical assistance following a reported air strike by government forces on March 9, 2014 in the northern city of Aleppo. (ZEIN AL-RIFAI/AFP/Getty Images) (credit:Getty Images)
(06 of29)
Open Image ModalA Syrian refugee family from Aleppo stay under a shelter during a rainy day on March 8, 2014, in the Uskudar district of Istanbul. (BULENT KILIC/AFP/Getty Images) (credit:Getty Images)
(07 of29)
Open Image ModalA Syrian rebel fighter shows female members of the 'Mother Aisha' battalion how to use a weapon in the Salah al-Din neighborhood of the northern Syrian city of Aleppo on March 8, 2014. (ZEIN AL-RIFAI/AFP/Getty Images) (credit:Getty Images)
(08 of29)
Open Image ModalFemale members of the 'Mother Aisha' battalion walk in a street holding weapons in the Salah al-Din neighborhood of the northern Syrian city of Aleppo on March 8, 2014. (ZEIN AL-RIFAI/AFP/Getty Images) (credit:Getty Images)
(09 of29)
Open Image ModalSyrian forces patrol a street in the town of Zara, in the province of Homs, on March 8, 2014 during fighting against rebels. (AFP/Getty Images) (credit:Getty Images)
(10 of29)
Open Image ModalA Syrian man runs past rubble as smoke billows in the background following a reported air strike by Syrian government forces during the Friday prayers in the Sukkari neighborhood of the northern city of Aleppo on March 7, 2014. (BARAA AL-HALABI/AFP/Getty Images) (credit:Getty Images)
(11 of29)
Open Image ModalSyrian emergency personnel extinguish a fire following a reported air strike by Syrian government forces on March 7, 2014 during the Friday prayer in the Sukkari neighborhood of the northern city of Aleppo. (BARAA AL-HALABI/AFP/Getty Images) (credit:Getty Images)
(12 of29)
Open Image ModalRebel fighters make their way to the front-line in the village of Morek, in the countryside of the Syrian city of Hama, on March 7, 2014. (Ali Nasser/AFP/Getty Images) (credit:Getty Images)
(13 of29)
Open Image ModalFruit and vegetable vendors are seen stationed next to the debris of a building in the northern city of Aleppo on March 7, 2014. (ZEIN AL-RIFAI/AFP/Getty Images) (credit:Getty Images)
(14 of29)
Open Image ModalA couple watch as members of the Syrian emergency personnel clear up the damage caused by air strikes on the northern Syrian city of Aleppo on March 7, 2014. (MOHAMMED AL-KHATIEB/AFP/Getty Images) (credit:Getty Images)
(15 of29)
Open Image ModalA rebel fighter runs for cover as a mortar is launched towards pro-regime fighters during clashes in the Sheikh Najjar district on the outskirts of the northern Syrian city of Aleppo on March 6, 2014. (MOHAMMED AL-KHATIEB/AFP/Getty Images) (credit:Getty Images)
(16 of29)
Open Image ModalSyrian emergency services personnel help a wounded man following an air strike by government forces on the Sahour neighbourhood of the northern Syrian city of Aleppo on March 6, 2014. (KHALED KHATIB/AFP/Getty Images) (credit:Getty Images)
(17 of29)
Open Image ModalOpposition fighters fire a heavy machine gun from a vehicle during clashes with government forces in the town of Khan Sheikhun, in Syria's Idlib province on March 6, 2014. (GHAITH OMRAN/AFP/Getty Images) (credit:Getty Images)
(18 of29)
Open Image ModalA Syrian man breathes through an oxygen mask as he is trapped under the rubble following an air strike by government forces on the Sahour neighbourhood of the northern Syrian city of Aleppo on March 6, 2014. (KHALED KHATIB/AFP/Getty Images) (credit:Getty Images)
(19 of29)
Open Image ModalA Syrian man holds a crying girl as he gestures following an air strike by government forces on the Sahour neighbourhood of the northern Syrian city of Aleppo on March 6, 2014. (Fadi al-Halabi/AFP/Getty Images) (credit:Getty Images)
(20 of29)
Open Image ModalSyrians look at the destruction following an airstrike by government forces on the northern Syrian city of Aleppo on March 5, 2014. (BARAA AL-HALABI/AFP/Getty Images) (credit:Getty Images)
(21 of29)
Open Image ModalA Syrian girl walks in the street following an airstrike by government forces on the northern Syrian city of Aleppo on March 5, 2014. (BARAA AL-HALABI/AFP/Getty Images) (credit:Getty Images)
(22 of29)
Open Image ModalPro-government fighters hold the Syrian flag as they pose for a photo in the village of al-Sahel, near the rebel held town of Yabrud, nearly 80 kilometres north of Damascus, on March 4, 2014. (STR/AFP/Getty Images) (credit:Getty Images)
(23 of29)
Open Image ModalOpposition fighters fire weapons during clashes with government forces in the Sheikh Najjar district on the outskirts of the northern Syrian city of Aleppo on March 3, 2014. (ZEIN AL-RIFAI/AFP/Getty Images) (credit:Getty Images)
(24 of29)
Open Image ModalRebel fighters are seen inside a building in the northern Syrian city of Aleppo on March 3, 2014. (MAHMUD ABDEL RAHMAN/AFP/Getty Images) (credit:Getty Images)
(25 of29)
Open Image ModalRebel fighters position their tanks in the area of Khanasser, south of the northern Syrian city of Aleppo, on March 3, 2014. (OBAIDA AL-SHAMI/AFP/Getty Images) (credit:Getty Images)
(26 of29)
Open Image ModalRebel fighters hold a position near the front line on March 2, 2014 in the Sheikh Najjar district on the outskirts of the northern Syrian city of Aleppo. (BARAA AL-HALABI/AFP/Getty Images) (credit:Getty Images)
(27 of29)
Open Image ModalA rebel fighter stands back as a rocket is launched towards a pro-government forces position in the Syrian town of Khan Sheikhun, in Idlib province, on March 2, 2014. (GHAITH OMRAN/AFP/Getty Images) (credit:Getty Images)
(28 of29)
Open Image ModalA rebel fighter looks through a barricaded window in the northern Syrian city of Aleppo on March 2, 2014. (MAHMUD ABDEL RAHMAN/AFP/Getty Images) (credit:Getty Images)
(29 of29)
Open Image ModalA picture taken on March 1, 2014 shows the wreckage of a Syrian army helicopter after Islamic State of Iraq and the Levant (ISIL)'s fighters allegedly destroyed it when they left the Meng Military Airport, in the northern Syrian city of Aleppo, to prevent other opposition groups taking it over. (MOHAMMED AL-KHATIEB/AFP/Getty Images) (credit:Getty Images)