"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus
The Pentagon said it was monitoring events because more than 120 US defence personnel and contractors, including 35 civilians, are in the Tbilisi area to train Georgian forces for deployment in Iraq.
Lithuania, a staunch ally of Mr Saakashvili, sent its foreign minister on a fact-finding mission to Georgia yesterday.
The EU said it was in contact with international partners including Russia, the United States, Georgia and the Organisation for Security and Cooperation in Europe about the situation.
Georgia, which borders the Black Sea between Turkey and Russia, was ruled by Moscow for most of the two centuries preceding the break-up of the Soviet Union.
A staunch US ally, it has angered Russia by seeking Nato membership – a bid Moscow regards as part of a western effort to weaken its influence in the region.
The separatist administration in South Ossetia has been trying to gain formal independence since breaking away in a civil war in the 1990s. South Ossetia has run its own affairs since fighting for independence from Georgia in 1991-92, in the aftermath of the collapse of the Soviet Union.
It has declared independence, though this has not been recognised by any other country.
Russia has troops in the region, on a peacekeeping mandate. But Moscow also supports the separatists.
Mr Saakashvili has vowed to bring South Ossetia and another breakaway region, Abkhazia, back under full Georgian control.