The Security Service of Ukraine know Ukrainian companies providers that despite the ban of Russian Internet services and websites on the territory of Ukraine continue working with this market segment, SBU Chief Vasyl Hrytsak has said.

"You know that Russians spread information how to access blocked [Russian] social networks. We are tracking these things… Yes, we know [Ukrainian companies that are working on the market], but I do not want to name them, as we are working," he said at a briefing in Kyiv on Thursday.

Asked if the fact that these companies are left on the Ukrainian market is a threat to the national security, he said they are and that is for sure.