KYIV, May 7 (Reuters) - Ukrainian air defences shot down a Russian hypersonic missile for the first time during an attack on the capital Kyiv this week, the Air Force said on Saturday (May 6), in a potentially major setback for the Kremlin's campaign of long-range air strikes.

The Kinzhal, which means "dagger" in Russian, is one of six "next generation" weapons unveiled by President Vladimir Putin in 2018 when the Russian leader boasted that it cannot be shot down by any of the world's air defence systems.

Ukrainian Air Force Commander Mykola Oleshchuk said the Kh-47 Kinzhal had been shot down on Thursday night over the region outside Kyiv. The Air Force said it had been taken down by a US Patriot air defence system.

"I congratulate the Ukrainian people on the historic event. Yes, we shot down the 'unparalleled' Kinzhal," he said on the Telegram app.

The US Patriot system is one of an array of sophisticated air defence units supplied by the West to help Ukraine repel a months-long Russian campaign of air strikes that has targeted critical infrastructure, power facilities and other sites.

Hundreds of civilians have been killed in the attacks that Russia stepped up in October ahead of winter. The strikes failed to cripple the power grid but caused sweeping power cuts and other outages. Russia denies targeting civilians.

Russia, which did not immediately comment on Ukraine's statement about the Kinzhal, has in the past boasted that the missile has no equivalent in the West.

The air-launched ballistic missile, which can reach speeds of up to Mach 10 (12,350 kmh), is capable of carrying nuclear or conventional warheads. It has a reported range of 1,500 to 2,000 km.

Ukraine said the missile was fired during a drone attack on Kyiv and other cities in the early hours of Thursday.

The Air Force had not previously disclosed that a Kinzhal was used for the attack, although Kyiv officials said immediately that a ballistic missile had been involved.

The Thursday air strike came less than a day after Russia accused Ukraine of a failed attempt to assassinate President Vladimir Putin in a drone attack on the Kremlin citadel in Moscow and threatened to retaliate.

Moscow has since accused Washington of involvement in allegations denied by both Ukraine and the United States.

Russia has already intensified drone and missile attacks on Ukrainian regions over the past week as Kyiv prepares to launch a counter-offensive against Russian forces who have dug in across swathes of occupied land in the south and east.

US Patriot missiles were only delivered to Ukraine last month, officials said.

Kinzhal missiles have been used on several occasions in Ukraine. The first known use of the weapon in combat was when Russia said it had fired the missile at a munitions dump in southwestern Ukraine on Mar 19, 2022.

Ukraine's Air Force was previously seen as unable to shoot down ballistic missiles, which Russia used to strike residential areas and Ukraine's power infrastructure.

The Air Force on Saturday said it shot down eight Shahed drones launched by Russia on the eastern and south-east Ukrainian regions in an overnight attack.