'war' intensifies
Russia has sent thousands of troops to another Georgian breakaway region.
Russian troops poured into the first breakaway region, South Ossetia on Friday, hours after the capital of Georgia launched a major offensive to take back control of the province from pro-Russian separatists.
Moscow has accused the Georgians of carrying out "ethnic cleansing and genocide" in the region.
Russian officials say the death toll stands at 2,000 and 30,000 refugees from South Ossetia have fled to Russia. The superpower says two of its warplanes have been shot down, 13 of its soldiers killed and 70 wounded.
Georgia has withdrawn its forces from South Ossetia but Russia has sent a further 4,000 troops to the coast of one of Georgia's other breakaway regions, Abkhazia.
Georgian Interior Ministry official Shota Utiashvili said: "Georgia faces a humanitarian catastrophe."
A UN peacekeeping official has warned of an imminent military offensive by the Abkhaz who, like the South Ossetians, broke with Tbilisi in the early 1990s after a war.
UN assistant secretary-general for peacekeeping Edmond Mulet said: "At this point we are particularly concerned that the conflict appears to be spreading beyond South Ossetia into Abkhazia."
The UN Secretary-General Ban Ki-moon said he was "profoundly concerned over mounting tensions in the Abkhaz zone."
Russia was unbowed by Western criticism of its military offensive.
Russian Prime Minister Vladimir Putin said: "Russia's actions in South Ossetia are totally legitimate."
Mr Putin said Georgia's bid to join the Western alliance NATO - anathema to Moscow - was part of the problem.
