The fighting in the eastern suburbs of Damascus was still going on Sunday evening according to testimonies of activists in Syria, Al Jazeera's Anita McNaught reported from Istanbul.

While it is difficult to verify precise details, it appears at least 50 tanks were deployed on the outskirts of the capital on Sunday, and that the scene resembled urban warfare.

"There were 50 original tanks spread out through the eastern area, in an effort to bring under control … an act of defiance that the government clearly felt had gone far enough," she said.