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Syrian security inspect the site of an explosion in Syria's northern city of Aleppo February 10, 2012, in this handout photograph released by Syria's national news agency SANA. Twin bomb blasts hit Syrian military and security buildings in Aleppo, killing 25 people in what was the worst violence to hit the country's commercial hub since the 11-month uprising against President Bashar al-Assad began.
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Men help evacuate civilians at a site hit by what activists said was shelling by forces loyal to Syria's President Bashar al-Assad in Aleppo's Bustan al-Qasr district, August 16, 2013.
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Residents run from a fire at a gasoline and oil shop in Aleppo's Bustan Al-Qasr neighbourhood October 20, 2013. Witnesses said the fire was caused by a bullet fired by a sniper loyal to Syrian President Bashar al-Assad at the Karaj al-Hajez crossing, a passageway separating Aleppo's Bustan al-Qasr, which is under the rebels' control and Al-Masharqa neighborhood, an area controlled by the regime.
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A man holds the hand of a young girl who was killed during a recent Syrian Air force air strike in Azaz, some 47 km (29 miles) north of Aleppo, August 15, 2012.
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A father reacts after the death of two of his children, whom activists said were killed by shelling by forces loyal to Syria's President Bashar al-Assad, at al-Ansari area in Aleppo January 3, 2013.