Using force against pro-Moscow protesters in Ukraine would be "extremely dangerous," Russia's foreign minister warned Monday.
“They are announcing an anti-terrorist operation,” Sergey Lavrov told reporters, shortly before at least 100 pro-Russian separatists attacked the police headquarters in Ukraine's eastern city of Horlivka. “This hypocrisy is sweeping off scale. A decision to exercise force ... is extremely dangerous and those who encourage the current government in Kiev to do that will have to bear responsibility for it."
In all, separatists have seized government buildings and security facilities in 10 cities in the country's largely Russian-speaking east.
In the city of Slovyansk, where armed men have seized two government buildings, a state security officer was killed over the weekend.
Ukrainian leaders blame Russia, which annexed Ukraine's Crimea region after Moscow-backed President Viktor Yanukovich fled after months of pro-Western protests, for inspiring and organizing a rash of rebellions in Slovyansk and other Russian-speaking towns in eastern Ukraine.
The crisis in Ukraine has brought relations between Russia and the West to their worst since the end of the Cold War in 1991.
In an emergency session of the U.N. Security Council late Sunday, Russian Ambassador Vitaly Churkin denied claims that Moscow was behind the violence.
"It is the West that will determine the opportunity to avoid civil war in Ukraine. Some people, including in this chamber, do not want to see the real reasons for what is happening in Ukraine and are constantly seeing the hand of Moscow in what is going on," Churkin said.
In response, U.S. Ambassador Samantha Power said, "These are not protests, these are professional military operations."
Reuters and The Associated Press contributed to this report.