Russia was swept up in patriotic fervour Friday for bringing Crimea back into its territory, with tens of thousands of people thronging Red Square waving flags and chanting "Crimea is Russia!" as a parliamentary leader declared that the peninsula would be welcomed as an "equal subject" of Russia.
The semi-autonomous region belongs to Ukraine, but the local parliament has called a March 16 referendum on whether Crimea should join Russia, a move President Barack Obama has called a violation of international law.
Tensions in Crimea were heightened late in the evening when pro-Russian forces tried to seize a Ukrainian military base in the port city of Sevastopol, according to the Ukrainian branch of the Interfax news agency. No shots were fired, but stun grenades were thrown, according to the report, citing Ukrainian officials.
About 100 Ukrainian troops are stationed at the base and they barricaded themselves inside one of their barracks, and their commander began negotiations, the report said. Crimea's pro-Moscow leader denied any incident at the base.
In the week since Russia seized control of Crimea, Russian troops have been neutralizing and disarming Ukrainian military bases on the Black Sea peninsula. Some Ukrainian units, however, have refused to surrender.
Crimea's new leader has said pro-Russian forces numbering more than 11,000 now control all access to region and have blockaded all military bases that haven't yet surrendered.
Foreign Minister Sergey Lavrov warned U.S. Secretary of State John Kerry that sanctions over Russian actions in Crimea could backfire, the ministry said in a statement. In a telephone conversation, Lavrov urged the U.S. not to take "hasty, poorly thought-out steps that could harm Russian-U.S. relations, especially concerning sanctions, which would unavoidably boomerang on the U.S. itself," the statement said.
The strategic peninsula has become the flashpoint in the battle for Ukraine, where three months of protests sent President Viktor Yanukovych fleeing to Russia. Moscow calls the new Ukrainian government illegitimate, and has seized control of Crimea, where it has a major naval base on the Black Sea.
Although President Vladimir Putin said Tuesday that Russia has no intention of annexing Crimea, he insisted that its residents have the right to determine the region's status in the referendum.
Crimea would be the first territory to join Russia since the breakup of the Soviet Union in 1991. South Ossetia and Abkhazia, which broke away from Georgia after a brief 2008 war with Russia, have been recognized as independent by Moscow, but there have been few serious moves to enable them to join Russia.
For Putin, Crimea would be a dazzling acquisition, and would help cement his authority with a Russian citizenry that has in recent years shown signs of restiveness and still resents the loss of the sprawling empire Moscow ruled in Soviet times.