The attack, deep into Russian territory, came a day after Kyiv launched one of the largest drone attacks on Moscow, according to the Russian authorities.

Kyrylo Budanov, the head of the HUR, said in an interview with American website The War Zone that about 50 drones were involved in the attack on the electronic intelligence center, Ostafyevo Airport, and the Millerovo airbase in the Rostov region in southern Russia.

The precise location of the targeted electronic intelligence center remains undisclosed, and it is currently unclear how much damage, if any, has been done to the target locations.

“We are checking now,” said Budanov.

He also said that an earlier attack by around 10 unmanned aerial vehicles on the Russian Savasleyka airbase destroyed a MiG-31 interceptor, and two Il-76 transport aircraft.