Russia has carried out one of its largest strikes on Ukraine including with nuclear-capable hypersonic missiles that hit cities and knocked off back-up power at Europe’s largest atomic plant.

Of the more than 80 rockets fired, six were nuclear-capable hypersonic Kh-47 Kinzhal air-to-surface missiles, according to Ukrainian officials. The assault has left much of Kyiv without electricity.

Russia has never before fired so many Kinzhals in one attack, said Yuriy Ignat, spokesperson for Ukraine’s air force, who added that Russia only had dozens of these missiles. The barrage included other types of missiles Ukraine was unable to intercept, such as X-22 supersonic missiles.

Among Moscow’s targets were residential areas in Kyiv and Europe’s largest nuclear power plant at Zaporizhzhia, whose back-up power was cut off in the attack, according to nuclear power company Energoatom.

Josep Borrell, the EU’s chief diplomat, said on Thursday that 40 per cent of Kyiv’s population was without electricity as a result of the strikes, along with some blackouts in other parts of the country.

The Zaporizhzhia plant was forced to rely on diesel generators for cooling systems, the company said. Located in southern Ukraine and under Russian occupation since March 2022, the plant has been repeatedly hit by artillery strikes and has lost back-up power supply several times.

“Currently, the power plant is de-energised and stays in blackout mode for the sixth time during the occupation,” Energoatom said in a statement.

“If the off-site power supply to the plant cannot be restored . . . an accident may occur having radiation consequences for the whole world,” the company added.

The International Atomic Energy Agency said this was the first time the plant had lost all power since November and that the diesel generators, which it described as “the last line of defence”, only had fuel for 15 days.

In an emotional address to the IAEA board on Thursday, the agency’s director-general Rafael Mariano Grossi said: “What are we doing? How can we sit here in this room this morning and allow this to happen? This cannot go on.”

“I am astonished by the complacency — what are we doing to prevent this happening?” Grossi said. “Each time we are rolling a dice. And if we allow this to continue time after time then one day our luck will run out.”

The Russian defence ministry said the strikes were in retaliation for last week’s incursion by a pro-Ukrainian militia into Russia’s Bryansk border region.

“In response to terrorist acts in the Bryansk region organised by Kyiv on March 2, Russia’s military forces carried out a massive revenge strike,” the ministry said in a statement on Thursday. “The goal of the revenge strike has been reached. Critical elements of the Ukrainian military and energetic infrastructure have been hit.”

In addition to the attacks on energy infrastructure, explosions were also recorded in the capital city Kyiv and in the western Ukrainian region of Lviv, where officials said five civilians were killed.

“It’s been a difficult night. A massive rocket attack across the country,” Ukrainian president Volodymyr Zelenskyy said in a Telegram post. “The occupiers can only terrorise civilians. That’s all they can do. But it won’t help them. They won’t avoid responsibility for everything they have done.”

Additional reporting by Henry Foy in Brussels and Anastasia Stognei in Riga