Pro-Russian separatists who seized a provincial administration building in the eastern Ukrainian city of Donetsk proclaimed the region independent Monday — an echo of events prior to Russia's annexation of Crimea. Ukrainian authorities called the move an attempt by Russia to sow unrest.
The Interfax news agency said the activists demanded that a referendum be held no later than May 11 on the possible secession of the Donetsk region, which borders Russia.
Outside the administration building, a barricade of car tires and razor wire was built up to keep police from retaking it. Police said those inside the building were armed.
Speaking in a televised address, acting President Oleksandr Turchinov called the events gripping eastern regions — where pro-Russian activists seized government buildings in at least three cities Sunday — an operation undertaken by Russia to sow instability.
"Anti-terrorism measures will be adopted against those that took up weapons," Turchinov said, adding that parliament would convene Tuesday to consider tougher penalties for separatist actions and even ban parties that engage in separatism.
In a video posted on the Internet, an unidentified pro-Russia activist in the Donetsk government headquarters asked Russian President Vladimir Putin to send "peacekeeping troops" to the region.
"Without your support, without the support of Russia, it will be hard for us to resist the Kiev junta on our own," he said, referring to the interim authorities that took power after the overthrow of Moscow-backed President Viktor Yanukovych in February.
Earlier in the day, Ukrainian Prime Minister Arseniy Yatsenyuk also accused Russia of being behind the unrest that broke out in the country's eastern provinces Sunday and of seeking to sow instability as a pretext for sending troops across the border.
"The plan is to destabilize the situation, the plan is for foreign troops to cross the border and seize the country's territory, which we will not allow," he said, adding that those taking part in the unrest have distinct Russian accents.
Yatsenyuk said Russian troops remain stationed within 30 kilometers (19 miles) of the border.
Eastern Ukraine was the heartland of support for Yanukovych, who fled to Russia after months of protests. About half of the region's residents are ethnic Russians, many of whom believe Ukraine's acting authorities are nationalists who will oppress Russians.
Ukraine's interim authorities deny they are infringing the rights of the ethnic Russian population and there has been no evidence of Russians in Ukraine facing harassment.
Since Crimea held a secession referendum and then was annexed by Russia in March, calls for similar votes in Ukraine's east have emerged.
The international community has expressed growing anxiety over the large Russian troop movements along the Ukrainian border. NATO says up to 40,000 Russian troops have mobilized and present a distinct threat to Ukraine. Russia, for its part, says it has the right to move its troops wherever it wants on its own territory.
Also Monday, Interfax cited police in Donetsk as saying an armed group attempted to seize the regional state television broadcaster. The Interior Ministry said the gunmen fired into the air and police and guards in the building returned fire, Interfax reported.
"After that, the attackers fled to an unknown location," police were cited as saying.
On Sunday, pro-Russian crowds stormed government buildings in Donetsk, as well as Luhansk and Kharkiv, all cities located in Ukraine's heavily Russian-speaking east. Authorities say all the storming parties appeared to have been armed.
Pro-Russian demonstrations have taken place across eastern Ukraine over the past few weekends and official buildings have been occupied, but the rallies have generally fizzled out within hours. On Sunday, however, one witness in Donetsk said the crowd included large numbers of masked men who behaved more aggressively than at previous rallies.
On Saturday, Ukraine's Security Service said it had detained a 15-strong armed gang that was planning to seize power in the eastern province of Luhansk. The agency said it seized 300 machine guns, an antitank grenade launcher, a large number of grenades, five handguns and firebombs.
It was unclear whether that group was linked to those behind Sunday's disturbances.
In Russia, the ITAR-Tass state news agency cited the deputy speaker of the upper house of parliament, Ilyas Umakhanov, as saying he didn't see the situation in Donetsk as a replay of events in Crimea.
"I don't think this situation automatically reflects what happened in Crimea ... from the judicial, historical and legal points of view, it demands a separate assessment," Umakhanov said.