DONETSK, Ukraine, APRIL 14, 2014 -- The deadline for protesters in the eastern part of Ukraine to put down their weapons and leave occupied buildings has come and gone, but the "anti-terrorist operation" vowed by Ukraine's acting president has yet to materialize.
The 9 a.m. local deadline expired a few hours before protesters in the eastern town of Horlivka stormed the local police headquarters, enlarging the map of places in Ukraine that have seen recent unrest to more than a dozen. Later, a municipal building in Zhadinivka was attacked.
Ukraine's acting president accused Russia Sunday night of being behind the violence and warned of "a full-scale antiterrorist operation engaging the armed forces of Ukraine."
"We will not allow Russia to repeat the Crimean scenario in the eastern regions of Ukraine," President Oleksandr Turchynov added, referring to Russia's swift annexation of the Crimean Peninsula last month.
For more than a week, anti-government protesters have occupied government buildings across the eastern provinces that border Russia. For the most part, they have demanded "federalization," giving them greater autonomy from the government in Kiev that many here feel abandoned by and describe as "fascists" and "criminals."
Some would also like to see this part of the country - like Crimea - join Russia.
Turchnynov softened his tone today, telling parliament that he is not against holding a referendum next month alongside presidential elections slated for May 25.
"It's not a confrontation between Ukrainians, but covert and now no longer covert aggression by the Russian Federation against our country," he added.
Two buildings - including a police station - were seized Saturday in the town of Sloviansk. The next morning, Ukraine's interior minister announced an operation to take them back but Ukrainian forces never appeared to enter the town.
Instead, a gun battle took place outside that left at least one Ukrainian officer dead. By Sunday night, checkpoints ringed the town, controlled by protesters, some of whom were defected Ukrainian soldiers.
Ukraine and the United States have repeatedly accused Russia of fomenting the violent unrest, which Russia's Foreign Minister Sergei Lavrov again denied today.
"It has all the tell-tale signs of what we saw in Crimea," the U.S. ambassador to the United Nations Samantha Power told ABC News’ “This Week” Sunday. "There's nothing grassroots seeming about it. Those forces are doing in each of the six or seven cities that they've been active in exactly the same thing, so certainly it bears the tell-tale signs of Moscow's involvement."
The White House could impose more sanctions on Russia this week, Power added, if Russia continues meddling.
In a statement titled "Russian Fiction," the U.S. State Department listed 10 Russian claims it says are lies. Among them were the assertions that Russian agents are not in Ukraine, that ethnic Russians are under threat and that civil war is coming to Ukraine.
But fear of war here was raised Sunday night when Russia called Ukraine's threatened crackdown against protesters a "criminal order." Moscow has warned Kiev against cracking down against Russian speakers, threatening intervention.
Moscow also accused CIA Director John Brennan of flying to Kiev to help coordinate a Ukrainian response to the unrest, which the CIA vehemently denied.
"The claim that Director Brennan encouraged Ukrainian authorities to conduct tactical operations inside Ukraine is completely false," a CIA spokesman said, declining to say whether Brennan had indeed visited Kiev.