Kiev: A group of pro-Russian activists, which had seized government buildings in Ukraine`s eastern city of Donetsk, proclaimed the region`s independence from Kiev Monday, local media reported.
The protestors announced the creation of People`s Republic of Donetsk and set a referendum for May 11 to validate the decision, Xinhua reported.
The activists called on Russia to send a "peacekeeping mission" to Donetsk if Kiev blocked the vote.
The move came after pro-Russian demonstrators seized the government buildings in three eastern Ukrainian cities -- Donetsk, Lugansk and Kharkov -- Sunday night, demanding that referendums be held to secede from Ukraine and join Russia.
An overwhelming majority of Crimeans voted to join Russia at a similar referendum in the Crimean peninsulaon March 16.
Two days later, Russian President Vladimir Putin and Crimean leaders signed a treaty to make Crimea and the city of Sevastopol part of Russian territory.
Meanwhile, acting President Alexandr Turchynov vowed Monday to launch a major counter-terrorism operation against separatist movements in the country`s eastern regions.
"We will carry out anti-terrorist activities against armed secessionists," Turchynov said in a nationwide address.
Ukrainian authorities had set up a special anti-crisis headquarters and tightened control on the country`s eastern borders in a bid to suppress separatism, he said.
Turchynov blamed Russian intelligence agencies for aiding Ukraine`s secessionists, saying that Moscow was willing to "destabilise the situation in Ukraine by overthrowing the government and disrupting presidential elections".