Russian cities and communities are busy preparing Victory Day WW2 memorial events all across the country ahead of Saturday, and so security is already on edge and on high alert, especially in the Moscow area, given that Ukraine's devastating cross-border drone attacks have persisted and expanded of late.

On Friday air traffic at 13 airports across southern Russia was suspended after drones struck a building at a regional air navigation center in Rostov-on-Don, Russia's transport ministry confirmed. This was the crucial air traffic control center for the whole region, and so its being taken offline has had significant impact.

Regional media has listed that it halted flights to and from airports in Astrakhan, Vladikavkaz, Volgograd, Gelendzhik, Grozny, Krasnodar, Makhachkala, Magas, Mineralnye Vody, Nalchik, Sochi, Stavropol and Elista.

"The regional air traffic control center in Rostov-on-Don, which manages air traffic in southern Russia, has been temporarily adjusted due to the Ukrainian drone strike ... personnel are safe, and equipment is being assessed" to determine whether operations can be restored, the ministry said on Telegram.

According to the Amsterdam-based Moscow Times, "Aeroflot, Pobeda, Nordwind and Rossiya Airlines said they were adjusting their flight schedules for Friday and would need to cancel some flights. At least 14,000 passengers were stuck due to delays and cancellations, the Association of Tour Operators of Russia said."

"Russia's Transportation Minister Andrey Nikitin asked major airlines to coordinate with the state-owned Russian Railways and the Unified Transportation Directorate to arrange for trains and buses to transfer passengers from canceled flights," the report noted.

On the same day, over 260 drones were intercepted across various sectors of the country - which suggests that in total at least several hundreds were sent. Once again, some of them reached as far away as the Perm region in the Ural Mountains.

The drone waves have continued despite that Russia unilaterally announced a ceasefire corresponding with V-Day events commemorating victory over Germany in WW2. The ceasefire runs May 8-10; however, Ukraine has not acknowledged this.

Still, the Defense Ministry is acting as if it is on and it is official, having announced in a statement Friday morning that it has observed 1,365 violations by Ukraine since midnight.