A rebel fighter runs through dust towards an area damaged by what activists said were barrel bombs dropped by warplanes loyal to Syria's President Bashar al-Assad in Aleppo's al-Shaar neighborhood November 6, 2014. REUTERS/Rami Zayat 

A man holding walkie-talkies runs towards a site damaged by what activists said were barrel bombs dropped by warplanes loyal to Syria's President Bashar al-Assad, in Aleppo's al-Shaar neighborhood November 6, 2014. REUTERS/Rami Zayat 

A man carries a child, injured by what activists said were barrel bombs dropped by warplanes loyal to Syria's President Bashar al-Assad, in Aleppo's al-Shaar neighborhood November 6, 2014. REUTERS/Rami Zayat 

Residents run past damaged buildings after what activists said were barrel bombs dropped by warplanes loyal to Syria's President Bashar al-Assad in Aleppo's al-Shaar neighborhood November 6, 2014. REUTERS/Rami Zayat 

A Free Syrian Army fighter places a mortar shell into a mortar launcher during clashes with forces loyal to Syria's President Bashar al-Assad in the Handarat area, north of Aleppo November 6, 2014. REUTERS/Hosam Katan 

A man reacts as he helps another, who is injured from what activists said were barrel bombs dropped by warplanes loyal to Syria's President Bashar al-Assad, in Aleppo's al-Shaar neighborhood November 6, 2014. REUTERS/Rami Zayat 

A Free Syrian Army fighter fires his weapon during clashes with forces loyal to Syria's President Bashar al-Assad in the Handarat area, north of Aleppo November 6, 2014. REUTERS/Hosam Katan 

ATTENTION EDITORS - VISUAL COVERAGE OF SCENES OF INJURY
A man carries a child, injured by what activists said were barrel bombs dropped by warplanes loyal to Syria's President Bashar al-Assad, in Aleppo's al-Shaar neighborhood November 6, 2014. REUTERS/Rami Zayat (SYRIA - Tags: CIVIL UNREST CONFLICT TPX IMAGES OF THE DAY) 

Free Syrian Army fighters prepare a mortar shell during clashes with forces loyal to Syria's President Bashar al-Assad in the Handarat area, north of Aleppo November 6, 2014.REUTERS/Hosam Katan 

A girl inspects damage of collapsed buildings after what activists said was a U.S.-led air strike on Kafar Joum village in West Aleppo countryside November 6, 2014. REUTERS/Stringer 

A Free Syrian Army fighter sits in shooting position during clashes with forces loyal to Syria's President Bashar al-Assad at the Karam Barre frontline beside Al-Maysar neighborhood of Aleppo November 2, 2014. REUTERS/Hosam Katan 

A man inspects the damage to collapsed buildings after what activists said was a U.S.-led air strike on Kafar Joum village in West Aleppo countryside November 6, 2014. REUTERS/Stringer 

A Free Syrian Army fighter rests beside weapons inside a safehouse on the Amerya frontline in Aleppo November 5, 2014.REUTERS/Hosam Katan 

Free Syrian Army fighters prepare a locally-made weapon launcher during clashes with forces loyal to Syria's President Bashar al-Assad on the Amerya front in Aleppo November 5, 2014.REUTERS/Hosam Katan 

Free Syrian Army fighters run with their weapons during clashes with forces loyal to Syria's President Bashar al-Assad on the Amerya front in Aleppo November 5, 2014.REUTERS/Hosam Katan 

A Free Syrian Army fighter sits in a shooting position behind sandbags, during clashes with forces loyal to Syria's President Bashar al-Assad at the Karam Barre frontline, beside Al-Maysar neighborhood of Aleppo November 2, 2014. REUTERS/Hosam Katan 

A damaged vehicle parks beside collapsed buildings after what activists said was a U.S.-led air strike on Kafar Joum village in West Aleppo countryside November 6, 2014. REUTERS/Stringer 

ATTENTION EDITORS - VISUAL COVERAGE OF SCENES OF DEATH OR INJURY

A man carries a dead child after what activists said were barrel bombs dropped by warplanes loyal to Syria's President Bashar al-Assad in Aleppo's al-Shaar neighborhood November 6, 2014. REUTERS/Abdalrhman Ismail (SYRIA - Tags: POLITICS CIVIL UNREST CONFLICT) 

Free Syrian Army fighters rest at the Karam Barre frontline beside Al-Maysar neighborhood of Aleppo November 2, 2014. REUTERS/Hosam Katan