Syrian troops have moved in with tanks to retake Damascus suburbs from armed rebels.
This amateur video appears to show the military launching the offensive in Ghouta, a suburb on the outskirts of the capital.
They also say 14 civilians and five members of the rebel Free Syrian army were killed.
The escalation in violence led to the suspension of the Arab League monitoring mission.
Observers were sent last month to assess whether President Bashar Assad was keeping his vow to halt the bloodshed.
The Arab League will brief the UN on Tuesday and Ban-Ki Moon once again called on Assad to stop the crackdown.
Meanwhile, Syrian expatriates gathered in Istanbul to call on President Assad to step down after ten months of unrest.
The UN estimates more than 5,000 people have been killed during that time.