(CNN) — Pro-Russian protesters took over a police building in an eastern Ukrainian city on Monday, even as a government deadline for demonstrators to leave occupied facilities in other cities passed with no immediate consequences.
Video from a demonstration in the eastern Ukrainian city of Horlivka showed protesters confronting police and walking through the building, which had small fires burning and broken windows. A severely beaten man in a police uniform was taken to an ambulance as onlookers shouted at him.
The seizure is a new complication for the government in Kiev. Acting President Oleksandr Turchynov had given pro-Russian protesters in other eastern Ukrainian cities until 2 a.m. ET to disarm or face a "full-scale anti-terrorist operation" by Ukraine's armed forces.
But the deadline passed with no sign that it was heeded in the eastern cities of Donetsk and Slaviansk. There was no movement at the regional government building in Donetsk, which has been occupied for more than a week. In Slaviansk, pro-Russian protesters milled around with makeshift shields outside the occupied police station.
Similar deadlines in the past came and went with no consequences.
Horlivka, with a population of about 300,000, became at least the 10th city or town in eastern Ukraine where activists have taken over security or government buildings in recent days.
When asked why the Ukrainian government had made no apparent move to evict protesters after the deadline passed, Ukrainian Deputy Foreign Minister Danylo Lubkivsky told reporters that the government still believes in a political solution. Although it wants to avoid bloodshed, the government still will protect the country's territorial integrity, he said Monday in Kiev.
Kiev blames Moscow
The unrest is the latest in a series of events ratcheting up tensions between Ukraine and Russia, which Kiev accuses of fomenting trouble in Russian-speaking eastern Ukraine.
After then-Ukrainian President Viktor Yanukovych backed out of a deal with the European Union in November in favor of closer ties with Russia, months of protests in Kiev led to his ouster in February.
Distrust among the population in eastern Ukraine -- the base of Yanukovych's power -- grew as the new national government shifted rapidly in a pro-Western direction. A short time later, pro-Russian elements occupied the Black Sea peninsula of Crimea, which Russia annexed in March. Since then, pro-Russian protesters have taken to the streets in eastern Ukraine and in some cases stormed and occupied buildings.
Kiev's fragile new government and the West accuse Russia of destabilizing the region as a pretext to potentially send in troops to protect the local Russian-speaking population.
NATO says Russian armed forces are massing on Ukraine's eastern border, while Moscow says they are merely carrying out military exercises.
Turchynov on Sunday issued a promise of amnesty for the activists -- including protesters as well as armed militants -- in eastern Ukraine but warned that anyone who continued to support the takeover of government buildings would be held responsible for their actions.
"We'll not allow any repetition of the Crimean scenario in the east of Ukraine," Turchynov said. "I have signed a decree that would allow those who did not shoot at our officers to lay down their arms and leave the occupied buildings by Monday morning without fear of being prosecuted."
After the deadline passed Monday, Turchynov said the majority of Ukrainians would back keeping Ukraine in one piece if a referendum is held along with presidential elections set for May 25.
"We do not mind having a referendum," Turchynov told members of parliament.
"Moreover, if there is (a) parliamentary decision to hold one together with the presidential elections, I am sure most people will express support of independent and unitary Ukraine."
Turchynov has said Russia was responsible for the bloodshed relating to the most recent protests. At least one Ukrainian soldier was killed in Sunday clashes between pro-Ukrainian crowds and pro-Russian protesters, a high-level source in Ukraine's Security Services told CNN.
In Moscow, Russian Foreign Minister Sergey Lavrov said any use of force against pro-Russian demonstrators in Ukraine will make it more difficult to create a lasting solution to the crisis.
A stable Ukraine is in Moscow's best interest, Lavrov said, also denying reports that Russian forces are active in the east. He refused to speculate about what events or actions would spur a military intervention by Russia into Ukraine.
Lavrov said he would hold off judgment on Turchynov's proposed referendum until Moscow sees the outline of the questions to be asked. He added that pro-Russian activists in the east must be given an active role in shaping a new constitution.
'Evidence of Russian involvement'
Ukrainian officials have placed blame for unrest in the eastern section of their country squarely on Russia. The new Ukrainian government said it was launching security operations against terrorists who are attempting to "destroy our country."
Giving no further details, it also said it had "concrete evidence of Russian special service involvement" in the pro-Russian protests and storming of buildings and would present it at an international meeting on the Ukraine crisis on Thursday.
Samantha Power, the U.S. ambassador to the United Nations, said Sunday the attacks in Slaviansk were "professional" and "coordinated" -- similar to Russia's incursion into the Crimean Peninsula last month.
The United States is prepared to step up sanctions against Russia if the recent actions in Ukraine continue, she said. Speaking on ABC's "This Week," she said the latest events in Ukraine bore "the telltale signs of Moscow's involvement."
"I think we've seen that the sanctions can bite. And if actions like the kind that we've seen over the last few days continue, you're going to see a ramping up of those sanctions," she said.
EU cutting tariffs for Ukraine
The European Union on Monday took another step to help Ukraine economically as Kiev's new government seeks closer ties to the West.
The EU's Foreign Affairs Council approved tariff cuts for most industrial and all agricultural goods, which will make it cheaper for Ukraine to export them to the European Union, saving Ukraine about 500 million euros a year, the council said.
The cuts will start at the end of April and last until November 1, by which time a fuller free-trade deal is expected to take effect.
European Union foreign policy chief Catherine Ashton is to meet this week with foreign ministers from the United States, Russia and Ukraine in Switzerland to discuss efforts to de-escalate the situation. EU foreign ministers will meet in Luxembourg on Monday to discuss the crisis.
On Sunday night, the U.N. Security Council held an urgent, previously unscheduled meeting to discuss the worsening crisis, where strong condemnations and accusations were traded.