What's in a name? Enough to anger Russia, which exercised its veto power in the UN Security Council and brought an end Monday to the nearly 16-year-old observer mission monitoring a cease-fire between Georgia and its breakaway Abkhazia region. Russia's veto late Monday toppled a Western plan to extend the life of the UN mission for another year, or even two more weeks, to work out a compromise. The vote was 10-1 with four abstentions - China, Vietnam, Libya and Uganda. The mission's mandate will now expire at midnight Monday in New York, requiring about 130 military observers and more than a dozen police to leave. Both the name - the UN Observer Mission in Georgia - and references to Georgia's territorial sovereignty were sticking points. "It is understandable," Russia's Foreign Ministry said in a statement Monday, "that in the new political and legal conditions most of the names and terms previously used in the old documents are inapplicable." UN Secretary-General Ban Ki-moon, who had recommended keeping the mission, said it would cease operations Tuesday despite his "regrets" at the lack of agreement that prompted its abrupt demise. Georgian Ambassador Alexander Lomaia said his nation would now "cooperate very closely with our friends," including the European Union and its monitoring mission to Georgia and human rights organizations also operating there. "It is of deep regret for the government of Georgia that the United Nations mission in Georgia has terminated its activity due to the rejection of a single country, due to the single hand raised," he said, adding that the UN's withdrawal is sure to be viewed negatively by local inhabitants. The vote coincided with clashes Monday between Georgian police and opposition activists pressing for the ouster of President Mikhail Saakashvili in the capital of Tbilisi on Monday. Officials said dozens of protesters were arrested and an Associated Press photographer saw masked officers armed with truncheons beating demonstrators, several TV journalists and camera crews. Following the Georgian-Russian war in the breakaway region of South Ossetia last August, Russia recognized the independence of both Abkhazia and South Ossetia. Georgia insists that both regions are still part of its territory, but Moscow insists they are not. The mission's abrupt termination follows months of talks between Russia, the United States, Britain, France and Germany. Also at stake is Georgia's pivotal location for energy supplies, serving as a route for oil and natural gas pipelines that can supply Western nations without going through Russia or Iran. As promised, Russian Ambassador Vitaly Churkin used his nation's right as one of the council's five permanent members to veto the draft resolution. "We need to get rid of this apparition," Russian Ambassador Vitaly Churkin told the council after casting the veto. "Our partners, however, prefer poison to medicine." He had said earlier Monday that the mission, known as UNOMIG, would "pass away peacefully" if Russia's demands weren't met. He had offered to extend the mission's mandate for one month on condition that the Security Council agree to delete all the "offensive references" in the resolution to names and sovereignty - an offer that was rejected by the Western powers. The Security Council could seek to restore a UN mission some time in the future, but if it met Russia's demands it would effectively recognize the independence of Abkhazia and South Ossetia and determine that Georgia no longer had sovereignty over the two areas, which the US and its European allies refuse to do. The mission was operating on a four-month extension granted by the Council in February to allow for more negotiations. The plan for extending it was put forward by the US, Britain and France - all of them permanent members - and non-permanent members Croatia, Turkey, Austria and Germany. It was modeled on Ban's recommendations last month for a continuing but unnamed UN "stabilization mission" to ensure no armed forces or military equipment operated in security zones extending 12 kilometers (7.5 miles) on each side of the cease-fire line. China is the fifth council member with veto power. US Deputy Ambassador Rosemary DiCarlo said the United States "deeply regrets" the Russian veto and reiterated the strong US commitment to Georgia's territorial integrity. "Extending the mandate would have allowed the UN to continue to carry out its role in monitoring the ceasefire, addressing security and humanitarian concerns on the ground, and helping create the conditions for the return of refugees and displaced persons," DiCarlo said. The US "will now consider measures to address a Georgia without a UN presence," including possibly bolstering the similar EU monitoring mission to Georgia, she said. "In the meantime, it is the civilian population that suffers by facing a tenuous security environment without an international presence in Abkhazia, Georgia." France's UN Ambassador Jean-Maurice Ripert said: "We cannot and we will not compromise on the territorial integrity of Georgia," The Black Sea province of Abkhazia has been independently run since 1993, when two years of fighting with Georgian troops ended with a UN-monitored cease-fire. Two-thirds of Abkhazia residents hold Russian passports, and along with South Ossetia it had sought independence or union with Russia.