Pro-Russian activists in Ukraine's Donetsk declare independence

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".