Syria’s army deployed armoured vehicles near central Damascus as troops battled rebels around the capital in what activists said could be a turning point in the 16-month uprising.

Syria’s ally, Russia, added its voice to rising calls for a truce so aid can be sent to violence-hit cities, after deadly clashes rocked a district of the capital near the heart of the embattled regime.

As tensions mounted further in Syria, UN Secretary-General Ban Ki-moon and Arab League chief Nabil Elaraby last night appointed Kofi Annan, Ban's predecessor as joint special envoy on the Syrian crisis.

Syria yesterday flatly rejected UN charges of crimes against humanity, even as monitors said troops killed dozens of civilians in the heaviest shelling of the protest city of Homs for days.