Opprørerne i Syria slo natt til mandag til mot et velstående område av Damaskus hvor ambassader og sikkerhetstjenester holder til.
Angrepet må ha kommet overraskende på regjeringssiden. 80 regjeringssoldater skal være drept.
Samtidig meldes det om stadig flere bilbomber. Al Qaida kan ha fått en fot innenfor.
Syria har for lengst passert grensen for borgerkrig, og den blir messy.
Some 80 troops loyal to Assad were killed in the fighting according to Al-Jazeera
A resident of Mazzeh district said automatic rifles and machine guns were used in the two-hour clash that ended at about 4 a.m. local time Monday.
Armed rebels are active in Damascus’ suburbs and satellite towns but rarely venture into the heart of the capital where President Bashar Assad’s troops are deployed in force.
An activist in the capital said the clash occurred near the Political Security Directorate building.
No one has claimed responsibility for any of the weekend attacks.
The string of large-scale bombings near government security buildings in Damascus and Aleppo that have added a mysterious element to the anti-government revolt. After other similar attacks, US officials suggested al-Qaida militants may be joining the fray.
A previously unknown Islamist group calling itself Al-Nusra Front to Protect the Levant claimed responsibility for previous attacks in a video posted online, saying it carried them out “to avenge the people of Homs.”
Heavy fighting reported in Damascus as rebels take on Assad stronghold
Dozens of regime forces reported killed in upscale neighborhood as armed rebels make rare venture into heart of capital