The Russian Defense Ministry said four of the five drones were downed by air defences on the outskirts of Moscow and the fifth was jammed by electronic warfare means and forced down.

The Russian military said Tuesday it fended off a Ukrainian drone attack on Moscow that prompted authorities to briefly close one of the city’s airports.

The attack, which follows previous similar raids on the Russian capital during the previous months, comes after a mutiny, launched by mercenary chief Yevgeny Prigozhin, which saw his Wagner troops approach Moscow in the biggest challenge to Russian President Vladimir Putin in more than two decades of his rule.

Ukrainian authorities, which generally avoid comments on attacks inside Russia’s proper territory, didn’t claim responsibility for the raid.

The Russian Defense Ministry said four of the five drones were downed by air defences on the outskirts of Moscow and the fifth was jammed by electronic warfare means and forced down.

Moscow Mayor Sergei Sobyanin said that there were no casualties or damage.

The drone attack prompted authorities to temporarily restrict flights at Moscow’s Vnukovo airport and divert flights to other Moscow airports. The restrictions were lifted after the drone attack was repelled.

The raid comes as Ukrainian forces have continued probing Russian defences in the south and the east of their country in the initial stages of a counter-offensive.

Russia, meanwhile, has continued its missile and drone barrage deep behind the front line.

Oleksandr Lysenko, mayor of the city of Sumy in northeastern Ukraine, said that three people were killed and 21 others were injured in a Russian drone strike Monday that damaged two apartment buildings.

Ukrainian President Volodymyr Zelenskyy said the attack also damaged the regional headquarters of the Security Service of Ukraine, the country’s main intelligence agency. He urged Western allies to increase supplies of air defence systems to help fend off Russian raids.