Ukraine's state security service on Tuesday said that pro-Russian separatists had placed explosives in a building they seized in the eastern city of Luhansk and were holding 60 people hostage, according to the Associated Press.
The activists have controlled the region's state security headquarters since storming it on Sunday and have denied both charges saying they had no explosives, but had seized an armoury full of automatic rifles, the AP reported. Witnesses said people appeared to be moving freely in and out of the building.
The Luhansk building was one of several seized by protesters in the east of the country demanding regional referendums on independence from Kiev, according to the AP. Protesters in Donetsk remain in control of the main regional authority building, but authorities ended the occupation in the city of Kharkiv.
Earlier Tuesday, Ukrainian authorities battled with pro-Russian protesters but regained control over a government building in Kharkiv, the country's second-largest city, evicting the protesters and detaining dozens, the AP reported.
Addressing parliament in Kiev, acting President Oleksandr Turchynov said security forces retook control of the Kharkiv administration building early Tuesday but several police were injured in the clashes with separatists, the AP reported. Interior Minister Arsen Avakov described the measure on his Facebook page as an "anti-terrorist operation."
Ukraine's interim authorities have achieved some success in quelling unrest that swept across eastern provinces Sunday, but rising tension threatens to undermine plans to hold a presidential election on May 25, according to the AP.
Secretary of State John Kerry threatened Russia with tougher economic sanctions on Tuesday if it fails to back down from its involvement in Ukraine, the AP reported. Kerry called the demonstrations in eastern Ukraine as a "contrived pretext for military intervention just as we saw in Crimea."
No clear leader or agenda has emerged from the obscure group of pro-Russian Donetsk activists behind the standoff, according to the AP.
