The barrage appeared to be one of the largest recent assaults in Ukraine’s campaign to damage Russia’s war machine on its home territory.

Ukraine struck Russian regions with a major drone and missile attack overnight, damaging at least two factories and forcing schools to close in a major southern Russian city, according to Russian officials and media.

Flight restrictions were imposed at five airports in Russia after Ukraine unleashed an attack reportedly with more than 200 drones and ballistic missiles. Alexander Bogomaz, the governor of the Bryansk region in western Russia, said Ukraine had launched a major missile attack but did not say which missiles had been used.

After a battle in Russia's snowy western region of Kursk this week, Ukrainian special forces scoured the bodies of more than a dozen slain North Korean enemy soldiers. Among them, they found one still alive.

Russia has leaned on its increasingly close ally North Korea for supplies of artillery shells and ballistic missiles to prosecute a grinding war in Ukraine. In October, the partnership entered a new phase as Pyongyang dispatched thousands of soldiers to bolster Russia’s armed forces.