MOSCOW, December 20. /TASS/. Ukraine is intensifying sabotage activities against Russia, Russian Federal Security Service Director Alexander Bortnikov said on Channel One television.

"Given what is going on along the engagement line, the Kiev regime is beginning to intensify covert warfare, sending in agents, saboteurs, establishing relations with people that are staying on our territory in order to harm us, as they say, behind the lines," he said.

"It would be desirable, of course, to do everything to pre-empt this. We are succeeding in this, in general," Bortnikov went on to say.

According to the official, the agency, also known as the FSB, is taking all necessary steps to identify cases of sabotage attacks.

The FSB director said that active work is underway. Many issues that the agency has in its crosshairs cannot be made public yet, but it will definitely be done, he added.