Syria opposition says 1,300 killed in Damascus attacks, chemicals used

(Adds detail, background) ISTANBUL, Aug 21 (Reuters) - A leading Syrian opposition figure said on Wednesday 1,300 people had been killed in attacks using chemical weapons by President Bashar al-Assad's forces around Damascus. "Today's crimes are ... not the first time the regime has used chemical weapons," George Sabra told a news conference in Istanbul. "But they constitute a significant turning point in the regime's operations ... This time it was for annihilation rather than terror." Syria denied activist reports on Wednesday that the army had used chemical weapons, describing the assertions as completely untrue. Video footage from districts east of the capital showed people choking, some of them foaming at the mouth, and many bodies with no visible signs of injuries. Sabra said the dead included 300 people killed in Hamouriyah, 150 in Douma and 100 each in the suburbs of Kafr Batna and Saqba to the east of central Damascus. Another 100 were killed in the town of Mouadamiya, west of the capital, he said. Western and regional countries called for U.N. chemical weapons investigators - who arrived in Damascus just three days ago - to check on the reports. (Editing by Andrew Heavens)