Almost 5,000 national security cases are being investigated by the SBU / Photo from UNIAN

These cases concern first of all the developments in eastern Ukraine, he said, according to

According to him, the SBU has information that different tools will be used in future to destabilize the situation in the country.

"[They may vary] from the distribution of leaflets with separatism propaganda in different cities of Ukraine and the recruitment of people from different social strata to attempts to blow up buildings and kidnap people," Vovk added.