Ukraine acting President Olexander Turchynov says the government is "helpless" to stop the uprising in the eastern regions of the country as pro-Russian activists continue taking government buildings.
"I would like to say frankly that at the moment the security structures are unable to swiftly take the situation in the Donetsk and Luhansk regions back under control," Turchynov said during a meeting with regional governors, BBC News reported. He added that security personnel "tasked with the protection of citizens" are "helpless."
Reuters reported that masked military forces took control of government offices in the town of Horlivka on Wednesday. The gunmen were apparently wearing the same military uniforms as other pro-Russian activists who have seized other towns in Ukraine.
Pro-Russian activists have captured a number of government buildings and taken hostages throughout the eastern regions of Donestsk and Luhansk. The acting president said there are fears agents in eastern Ukraine are aiding or co-operating with terrorist groups.
"Our task is to stop the spread of the terrorist threat first of all in the Kharkiv and Odessa regions," he stated.
Responding to international criticism, Russian President Vladimir Putin has rejected accusations that his government is responsible for stirring unrest in Ukraine.
Russia's Foreign Ministry said earlier in April that it is confident a resolution to the crisis can be achieved through peaceful means, and insisted that Putin's government is promoting stability in the region.
"We are firmly convinced that this can be achieved through, among other steps: real constitutional reform, which would ensure the legitimate rights of all Ukrainian regions and respond to demands from its south-eastern region to make Russian the state's second official language; firm guarantees on Ukraine's non-aligned status enshrined in its laws, thus ensuring its role as a connecting link in an indivisible European security architecture; and urgent measures to halt activity by illegal armed formations of the Right Sector and other ultra-nationalist groups," the Foreign Ministry said.
Turchynov stated, however, that Ukraine is in "full combat alert" amid fears Russian forces could invade, and said that there are tens of thousands of Russian troops stationed around Ukraine's border.
"The threat of Russia starting a war against mainland Ukraine is real," Turchynov said.
Ever since Russia's annexation of Crimea in March, fears have been mounting that further territories might break away, with reports of activists taking government buildings first appearing at the beginning of April.
Daniel Baer, the U.S. ambassador to the OSCE, a European security watchdog, told reporters in Vienna regarding such attacks: "I think it's very clear that what is happening would not be happening without Russian involvement."
The White House, which has accused Putin's government of escalating tensions in Ukraine, has imposed economic sanctions on Russia, including freezing U.S. assets of certain Russian officials and giving them travel bans to the U.S.
"This comes in the context of Russia continuing to violate the sovereignty and territorial integrity of Ukraine and completely failing to meet its commitments under the agreement that was reached in Geneva. That agreement did provide a basis for de-escalation. Yet, over the course of the last days and weeks we have not seen the Russians follow through in urging separatists to stay back in eastern Ukraine to, for instance, lay down their arms, vacate buildings, and begin a process of dialogue and lead to a de-escalation," a senior administration official said on a conference call on Ukraine sanctions on Monday.
"Because of that failure, the President convened a call with several of his European counterparts over the weekend. And those consultations led to a very strong G7 statement over the weekend that found that Russia was not meeting their commitments, and therefore urged additional targeted sanctions to impose a cost on Russia."