A global aid agency has called upon the international community to help broker an immediate ceasefire and protect civilians caught up in the conflict over Georgia's breakaway South Ossetia region.
Russian armed convoys entered Georgia on Friday after it launched an offensive to retake control of the South Ossetia region. Fierce fighting spilled into a second day on Saturday, with Russia threatening air strikes on Georgia's military bases.
"Thousands of civilians are in harm's way right now, including women and children," said David Womble, World Vision's national director for Georgia.
"The UN Security Council must make this matter a priority, and help broker an immediate ceasefire between the parties. If fighting continues, thousands of families will be forced to flee, and we could be faced with a humanitarian crisis."
President Bush, who had spoken recently with Russian President Dmitry Medvedev and Georgian President Mikhail Saakashvili, urged on Saturday an end to the violence.
"I'm deeply concerned about the situation in Georgia," Bush said in a statement to reporters while attending the Olympic Games in Beijing, according to The Associated Press. "The attacks are occurring in regions of Georgia far from the zone of conflict in South Ossetia. They mark a dangerous escalation in the crisis.
"The violence is endangering regional peace, civilian lives have been lost and others are endangered. We have urged an immediate halt to the violence and a stand-down by all troops. We call for an end to the Russian bombings, and a return by the parties to the status quo of Aug. 6."
Earlier, France, which currently holds the European Union's rotating presidency, announced on Friday that envoys from the EU, the United States and human rights body the Organization for Security and Co-operation in Europe were on their way to the troubled region to help secure a ceasefire.
Russian Foreign Minister Sergey Lavrov told reporters on Saturday that around 1,500 people had already been killed in fierce fighting.
World Vision called on both sides to allow the safe passage of humanitarian response teams and civilians fleeing from the conflict zone after the agency received reports that heavy fighting has made Tskhinvali, the main city in South Ossetia, completely inaccessible.
"We're hearing reports that the entire water supply to Tskhinvali has been shut off. Potable water is the number-one humanitarian need right now for the city and surrounding areas," said Womble.
World Vision is readying emergency supplies to assist people fleeing the conflict, and in neighboring North Ossetia the agency said it was preparing for an influx of displaced people from the South.