Rescuers put out a fire at an industrial facility after a massive Russian drone strike targeting the capital
Rescuers put out a fire at an industrial facility after a massive Russian drone strike targeting the capital AFP

Russia unleashed the "most important" assault by drones on Kyiv overnight Saturday-Sunday since the start of the invasion, but nearly all were destroyed, military authorities said.

Forty of the 54 drones launched targeted the capital, killing two people and wounding three.

"In total a record number of explosive drones launched were counted: 54!" Ukraine's air force said in a Telegram post on Sunday.

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The attack "took place over several waves and the air raid alert lasted more than five hours!"

"According to preliminary reports more than 40 Russian drones were destroyed by air defence" systems over Kyiv, the administration added.

With most of the drones being downed, "debris fell on a seven-storey building" in the capital's Golosiivskii district, killing one person and wounding another.

A fire broke out in a warehouse zone sending flames shooting 1,000 metres (3,300 feet) into the sky and also injuring one person, the administration said.

"The emergency services are at all the sites," the regional authorities said.

Near a petrol station in the Solomianskii area, a 41-year-old man died and a 35-year-old woman was wounded and hospitalised, said Kyiv's mayor, Vitali Klitschko.

It was the 14th drone attack on the Ukraine capital by Russia this month, the authorities said, noting an unprecedented number in a single month after Kyiv had been relatively spared at the start of the year.

The mayor described the assault as "massive" with drones "arriving from several directions at once".

Sunday was to be celebrated as the capital's special day, prompting the authorities to make an ironic statement: "Today the enemy decided to 'congratulate' the population on Kyiv Day with the help of their killer drones".

The 54 attack drones were launched "from the regions of Briansk and Krasnodar" in Russia, said the air force, adding that 52 were destroyed.

Moscow was targeting "military installations and critical infrastructure in the centre of the country and in particular the Kyiv region", it said.

As the drone war rages, Russia has over the part few weeks seen its own territory attacked as well, blaming Kyiv for dozens of artillery, mortar and drone strikes on the southern Belgorod region.

The reports of drone attacks and sabotage raids in Russian regions bordering Ukraine come at a time when Kyiv says it is finalising plans for a major counter-offensive to recover lost territory, including the Crimea peninsula, occupied by Moscow's forces.

But the drones can also strike hundreds of kilometres inside Russia.

On Saturday, a building from where an energy pipeline is administered was damaged by two drones in western Russia, governor Mikhail Vedernikov said.

A drone also hit an oil operation in the Tver region, northwest of Moscow, according to Baza, a Russian media outlet with sources in the secret services.

The regional government said only that a drone had "fallen", causing no injuries.

The past week also saw an unprecedented two-day incursion from Ukraine claimed by two anti-Kremlin groups, with Russia using its air force and artillery to push back the fighters.

Russia's defence ministry has vowed an "extremely harsh" response to any further attacks on its soil.

Moscow has accused Kyiv -- and its Western supporters -- of the escalating number of attacks and sabotage operations, including on the most spectacular against the Kremlin on May 3, but Ukraine has denied involvement.

Foreign Minister Sergei Lavrov on Sunday said Western nations were "playing with fire" by agreeing to supply Ukraine with advanced US F-16 fighter jets.