Half of the Russian missiles fired at Ukraine on Tuesday evaded air defences as Kyiv struggled to cope with the threat posed by ballistic missiles.

At least six people were confirmed killed and 70 more injured by the long-range barrage across the country, authorities said.

Oleh Syniehubov, Kharkiv’s governor, said five of the dead and 51 wounded were in the eastern city, where 30 residential buildings had been damaged in the strikes.

Rescue workers sifted through the rubble for survivors, Ihor Terekhov, the city’s mayor, said.

In Kyiv, high-velocity projectiles slammed into apartment blocks and non-residential buildings, as the Ukrainian capital was awoken by the sound of air raid sirens.

Ukraine’s air force said air defence shot down 21 of the 41 Russian missiles, which were also aimed at Pavlohrad, in the Dnipropetrovsk region.

Twenty of the missiles were downed in the skies over Kyiv, the capital’s military administration said.

Officials said 22 people, including three children, had been wounded across at least three districts of the city.

Some of the damage occurred next to the United Nations office, resident coordinator Denise Brown said.

Russia has escalated its long-range barrages on cities and civilian infrastructure since late last year.

Its forces have taken to using more ballistic missiles, which can travel at speeds of more than 2,000mph, to evade Ukraine’s Soviet and Western air-defence systems.

Moscow has been accused of using ballistic missiles acquired from North Korea to carry out a number of these attacks.

Ukrainian forces have had success in taking down ballistic missiles with the US-supplied Patriot and the Franco-Italian Sampt/T systems, analysts said.

But given the country’s limited supply of the systems and their associated missiles, Russia has been able to attack areas less densely protected by the shield they provide.

“Interception rates vary dramatically based on the munitions the Russians use,” Jimmy Rushton, an independent analyst in Kyiv, said.

“Ballistics are extremely difficult to intercept and Ukraine only has a few systems – Patriot, Samp/T – that can intercept them, and they can only be employed in a limited number of locations.

“If the Russians fire them at areas that aren’t defended by one of these scare systems they can’t do much to stop them.”

Five of the 12 Iskander-M ballistic missiles fired by Russian forces on Tuesday were downed by Ukrainian air defences, according to the country’s air force.

Ukraine has had relative success in intercepting slower cruise missiles and drones, and is capable of protecting areas like Kyiv, which are covered by Western systems.