The European Union is very concerned by the fighting in South Ossetia and urges all parties to stop the violence, an EU official said.

"We are following this very closely, we are very concerned by how the situation is evolving," said the official, who asked not to be named. "We repeat our message to all parties to immediately stop the violence."

The European Union was in contact with international partners including Russia, the United States, Georgia and the Organisation for Security and Cooperation in Europe (OSCE), he said.

Fighting raged around the capital of Georgia's breakaway South Ossetia as Georgian troops and warplanes pounded separatist forces in a bid to re-take control of the territory.