The Armenian citizen, Armen Martirosyan, who figures in the Belavia aircraft incident, had been in direct contact with public organizations involved in a plan to destabilize the situation in Ukraine, the Ukrainian Security Service said.

"The immediate supervision and implementation of the plan is carried out by [Inal] Ardzinba, who is known both to the Security Service and the Foreign Intelligence Service, whereas liaising with our country's political movements and certain public organizations participating in protests, normally blindly, or for material remuneration, [was carried out by] the Armenian citizen Martirosyan," Anatoliy Dublyk, head of the national statehood protection department at the Ukrainian Security Service, said at a briefing on Friday.

According to him, this information was exposed when the materials from the hacked email account of Russian presidential adviser Vladislav Surkov was analyzed.

In the second half of November - early December "several regional councils are planning to conduct [...] sessions under slogans of decentralization to demand the practice of agreement-based relations between the Cabinet of Ministers and local councils," Dublyk said.

A number of regional councils have already made such decisions, which led to a criminal investigation, he said. "Inquiries continue, efforts are underway to gather evidence and give a legal assessment of the organizers who are behind preparations for the so-called sessions or forums," the security official said.

"The regions are also planning to conduct community gatherings and forums and subsequently a final all-Ukrainian forum of local councils. Direct demands for federalization are not envisaged. At the same time, the strategy selected is that of slow erosion of the central government. In other words, basically this is a plan to create conditions in order to paralyze central-government bodies," Dublyk said.

The Ukrainian Security Service has a plan to counter the intentions to destabilize the situation in Ukraine for the purposes of conducting early parliamentary elections, he said. "There is a plan, the Ukrainian Security Service and the Foreign Intelligence Service are employing whatever forces and resources are available. We are in close cooperation with police, other law enforcement agencies, courts, prosecutors," Dublyk said.

"If we did not have this plan, you know yourselves what would be in the streets of Kyiv [...]. The plan is effective, we are working round the clock," the head of the department said.

The actions of law enforcement agencies do not violate citizens' rights, he said. "People are entitled to take to the streets with demands, but when they are being used during protests [that is unacceptable]," the Ukrainian security official said.