According to Oscar Jonsson, PhD in Russian warfare at the Norwegian Defense Academy, there is information that a ballistic robot was involved in the attack.

Something that basically hasn't been used since the first month of the war, he says.

- The ballistic robots basically go up into the stratosphere and then come down at a tremendous speed, which makes them very difficult to shoot down with anti-aircraft.

According to Ukrainian authorities, important infrastructure was also attacked, and according to Oscar Jonsson, Russia has focused on this type of warfare since October.

- This is the ninth wave of major robot attacks.

And what you can see is that with each wave the electricity grid becomes more and more vulnerable, which leads to longer and longer blackouts in more places.