Two regional government buildings were seized in the eastern Ukrainian city of Kharkiv, though police say they were freed after overnight negotiations. According to other reports, pro-Russian groups seized a security building in the city of Donetsk and have weapons from another seized security service building in the nearby city of Luhansk.
The government has sent security officials to the region to contain the protests and say they will clear the protests without any bloodshed, but that looks increasingly unlikely as protesters are barricaded in several buildings.
The interim government in Kiev is worried this is going to escalate into a scenario similar to the one that led to the annexation of the Crimean peninsula. These worries are not unfounded as in Donetsk, an online video shows a man speaking in Russian to the people gathered: "I proclaim the creation of the sovereign state of the People's Republic of Donetsk."
Reports say that anti-government protesters in Donetsk plan to hold a referendum by May 11 to declare their independence from Ukraine.
The government in Kiev says this unrest is supported by Russia and former Ukrainian President Viktor Yanukovych. Interim President Oleksandr Turchynov says that this is another attempt by Russia to "dismember" Ukraine ahead of the presidential elections, which Russia is calling illegitimate.
In an emergency cabinet meeting, interim Prime Minister Arseniy Yatsenyuk said that the people who were involved in the unrest had distinct Russian accents -- evidence towards Moscow's effort to destabilize the country.
"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.
Ukraine and western nations have been on edge since Russia amassed 30,000 troops on Ukraine's eastern border, fearing that Russia would try to press further into the region.
Russia has since scaled down their military presence on the border and says they will not attempt to seize any territory other than Crimea unless they feel the safety of ethnic Russians in other Eastern European countries are threatened.
Russia's territorial aggression is not just heating tensions with Ukraine but with the entire Eastern European region. NATO has increased their presence in the Baltic states, and Czech President Milos Zeman says NATO should deploy troops to Ukraine if Russia crosses the border.
"If Russia decides to extend its territorial expansion to eastern Ukraine, the fun is over," he told Czech public radio on Sunday.
Tensions in Eastern Europe and between Russia and western nations are the highest since the Cold War.