A fresh barrage of deadly Russian strikes battered Ukraine on Friday, cutting water and electricity in major cities and piling pressure on the grid in sub-zero temperatures.

Kyiv residents in winter coats crammed into underground metro stations as air raid sirens rang out and Russian forces fired off dozens of missiles in one of the biggest broadsides targeting the Ukrainian capital since February.

AFP journalists reported loud explosions and Kyiv's mayor said water supplies were disrupted in a wave of nationwide attacks that also killed two in President Volodymyr Zelensky's hometown in the south.

Ukraine's second largest city Kharkiv, near the border with Russia, was left without electricity, its mayor said.

"I woke up, I saw a rocket in the sky," Kyiv resident 25-year-old Lada Korovai said. "I saw it and understood that I have to go to the tube."

"We live in this situation. It's a war, it's real war," she told AFP.

The onslaught is the latest of several waves of strikes targeting key infrastructure that began in October after a series of embarrassing battlefield defeats for Russia.

The central cities of Poltava and Kremenchuk were also without power and regional officials in Kryvyi Rig, where Zelensky was born, said rockets hit a residential building.

Kyiv water cuts

"Two people died," governor Valentyn Reznichenko said. Eight were injured, he added.

Oleksandr Starukh, head of the frontline Zaporizhzhia region, which houses Europe's largest nuclear power plant, said more than a dozen Russian missiles had targeted territory under Ukrainian control.

Kyiv meanwhile "withstood one of the biggest missile attacks since the beginning of the full-scale invasion. About 40 missiles were recorded in the capital's airspace," regional authorities said in a statement on social media.

"Thirty-seven of them were destroyed by air defence forces!" they added.

Kyiv Mayor Vitali Klitschko said there were disruptions to water supplies and that the metro had stopped running so people could shelter underground.

"Due to damage to the power system and emergency power outages, subway trains will not run until the end of the day today," city officials later announced online.

The Kyiv metro, a vital resource for the capital which had a pre-war population of three million, has been used as a city-wide bomb shelter since the Russian invasion.

About half of Ukraine's energy grid has been damaged in sustained attacks and the national provider warned Friday of emergency blackouts because of the "massive" wave of Russian attacks.

'Russian terror'

Temperatures in the Ukrainian capital hovered between minus one and three degrees Celsius (30 to 37 degrees Fahrenheit).

Foreign Minister Dmytro Kuleba called on Ukraine's allies to bolster supplies of weapons.

"For each Russian missile or drone aimed at Ukraine and Ukrainians there must be a howitzer delivered to Ukraine, a tank for Ukraine, an armoured vehicle for Ukraine," he said on social media.

"This would effectively end Russian terror against Ukraine and restore peace and security in Europe and beyond."

Fresh Russian shelling in the southern city of Kherson, recently recaptured by Ukraine, killed one person and wounded three more.

Kherson has been subjected to persistent Russian shelling since Moscow's forces retreated in November and power was cut in the city on Thursday.

The UN humanitarian coordinator for Ukraine, Denise Brown, said a woman working as a paramedic for the Ukrainian Red Cross was killed by Thursday's strikes in Kherson.

In the Russian-controlled region of Lugansk in eastern Ukraine, Moscow-installed officials said shelling from Kyiv's forces had killed eight and wounded 23.

Putin to visit Belarus

"The enemy is conducting barbaric shelling of cities and districts of the republic," the Russian-installed leader of Lugansk Leonid Pasechnik said on social media.

Moscow has said the strikes on Ukrainian infrastructure are a response to an explosion on the Kerch bridge connecting the Russian mainland to the Crimean peninsula annexed by Moscow in 2014.

The Kremlin has said it holds Kyiv ultimately responsible for the humanitarian impact of the strikes for refusing to capitulate to Russian negotiation terms.

Ukrainian defence officials have credited systems newly supplied by Western allies for downing Russian missiles and drones.

Defence officials said this week that Ukraine had shot down a swarm of more than a dozen Iranian-made attack drones launched at Kyiv.

Separately on Friday, Russian President Vladimir Putin announced he will visit Belarus next week for talks with his counterpart and ally Alexander Lukashenko.

Minsk said the pair will hold one-on-one talks as well as wider negotiations with their ministers on "Belarusian-Russian integration".