A video posted on the internet by opposition activists shows bodies lined alongside what they said was the Queiq River in the rebel-held Bustan al-Qasr neighborhood of Aleppo.
The Queiq River rises in Turkey and travels through government-held districts of Aleppo before it reaches Bustan al-Qasr.
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In an embarrassing setback for the president, Republicans failed to reach the number of votes to pass his new healthcare act into law.
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Some of Britain's biggest stars of the stage and screen will be honoured at Buckingham Palace later today.