It was the latest in an increasing number of strikes on Russian territory carried out by Kyiv, more than four years into Russia's full-scale invasion of Ukraine.

"Last night Ukrainian FP-5 Flamingos struck a military plant in Cheboksary that supplies the occupier's army with components for drones and missiles," Zelensky said.

He published footage purporting to show a missile flying toward its target, and plumes of smoke rising over Russian facilities.

Cheboksary is the main city in Russia's central Chuvashia region, located 1,000 kilometres (620 miles) away from the Ukrainian border.

The regional governor, Oleg Nikolayev, confirmed the city had been hit.

"Early this morning, Cheboksary came under rocket attack. We are working to determine the number of casualties and the extent of damage to infrastructure," Nikolayev said on Telegram.

Ukraine also hit an oil refinery in Russia's Samara region, as well as a Russian tanker in the Black Sea, its General Staff said.

Ukraine has developed its own missile called Flamingo but its use remains relatively rare.