Ukraine unleashed over 500 drones in overnight attacks targeting Russia killing at least three people, reports said.
Moscow has termed the attack as "the largest in over a year," state-run TASS news agency reported.
The attacks come in the aftermath of a wave of Russian strikes, which Ukrainian authorities said killed at least 25 people and injured dozens, CNN reported.
Russia's Defense Ministry has claimed it intercepted 556 Ukrainian drones overnight. Moscow Mayor Sergey Sobyanin said more than 120 drones were shot down. Sobyanian termed the drone raids by Ukraine as "massive."
Reports said four people were injured when drones damaged residential buildings in the western town of Istra. Drone fragments also reportedly fell on Sheremetyevo Airport, Russia's busiest air hub. Russia's Federal Aviation agency announced restrictions on operations at Vnukovo, Domodedovo, Sheremetyevo, and Zhukovsky airports. The nature of the curbs remain unclear.
Russia's Transport Ministry said 51 aircraft bound for Moscow had to be diverted to alternate airfields due to the curbs imposed by the administration. Authorities also said 32 flights reported delays of up to two hours due to the situation.
TASS has posted what it claims as images of the destruction but did not specify the locations. Construction workers suffered injuries at the entrance to the Moscow Refinery, according to the TASS report. The refinery's operations were not affected.
Ukraine had claimed Russia launched 287 drones overnight on Thursday and reported that at least nine people were injured in the Dnipropetrovsk region and Zaporizhzhia district. Authorities in Kiev said eight drones were shot down.
Russia's state-backed RT web site reported that though there have been several major UAV attacks on Moscow recently, the number of drones deployed by Kiev never exceeded 65. The report put the number of flights were delayed or canceled at more than 200.
The Russian defense ministry said drone interceptions were reported in areas bordering Ukraine including Belgorod, Kursk and Bryansk as well as deep interior areas including Kaluga, Tula, Smolensk, Pskov, Tver, Rostov and Krasnodar Regions. Strikes were also reported in regions near Crimea, the Black Sea and the Sea of Azov.
Earlier this month, Moscow had held a low-key Victory Day military parade following a wave of Ukrainian strikes deep inside Russia, mainly targeting oil refineries. Russia and Ukraine have exchanged 205 prisoners of war (PoW) in connection with the Victory Day ceasefire.
Ukraine described the exchange as the first stage of a wider exchange of 1,000 prisoners each, as part of the peace efforts brokered by US President Donald Trump on May 8, to coincide with a US-mediated three-day ceasefire for Russia's Victory Day commemorations.
