Russia pounded Ukraine with missiles and drones, killing at least 11 people, according to officials, after Western allies promised to supply tanks to help Ukraine fight Russia's invasion.

Air raid alarms sounded across Ukraine on Thursday as people headed to work. In the capital, Kyiv, crowds took cover in underground metro stations.

"Not a single room is left intact, everything got hit," said Halyna Panosyan, 67, surveying twisted sheets of corrugated metal, crumpled masonry and a big missile crater outside her ruined house in Hlevakha near Kyiv.

"There was an extremely loud strike that made me jump up. I was in the bedroom ... I was saved by the fact that the bedroom is on the other side of the house."

Russian forces trained tank, mortar and artillery fire on more than 60 towns and villages in an arc of territory extending from Chernihiv and Sumy regions in the north through Kharkiv region in the northeast and in the focal points of Russian attempts to advance in Donetsk region in the east - Bakhmut and Avdiivka.

Ukraine's military said it shot down 47 of 59 Russian missiles - some fired from Tu-95 strategic bombers in the Russian Arctic. Russia also launched 37 air strikes, 17 of them using Iranian-made Shahed-136 drones. All drones were downed, the military said.

Eleven people were killed and 11 wounded in the drone and missile strikes, which spanned 11 regions and also damaged 35 buildings, a State Emergency Service spokesperson said.

Japan on Friday tightened sanctions against Russia in response to its latest wave of missile attacks in Ukraine.

Russia responded with fury to news on Wednesday that Germany and the United States would send dozens of modern tanks to Ukraine. More tanks will come from Canada, Poland, Britain, Finland and Norway while several more allies including France, Spain and the Netherlands were considering sending tanks too.

ENERGY TARGETED

Rafael Grossi, head of the International Atomic Energy Agency (IAEA), who visited Ukraine last week, said IAEA monitors reported powerful explosions near Ukraine's Russian-occupied Zaporizhzhia nuclear power station and renewed calls for a security zone around the plant.

But Renat Karchaa, an adviser to the head of Rosenergoatom, the company operating Russia's nuclear plants, said the comments were unfounded and called it a "provocation".

Russia has in the past reacted to Ukrainian successes with massed air strikes that left millions without light, heat or water.

On Thursday, it appeared to follow that pattern. Prime Minister Denys Shmyhal said Russia's attacks targeted energy plants.

"I held an urgent meeting today about the energy situation - about the shortages that are occurring and repair work after the terrorists' strikes. Repair teams are working in those sites," President Volodomyr Zelensky said in an evening video address on Thursday.

The Kremlin said it saw the promised delivery of Western tanks as evidence of growing "direct involvement" of the United States and Europe in the 11-month-old war, something both deny.

Western allies have committed about 150 tanks while Ukraine has said it needs hundreds to break Russian defensive lines and recapture occupied territory in the south and east. Both Moscow and Kyiv, which have relied on Soviet-era T-72 tanks, are expected to mount new ground offensives in the spring.

After being promised modern tanks, Ukraine is now seeking Western fourth-generation fighter jets such as the US F-16, an adviser to Ukraine's defence minister said.

In Odesa, the Black Sea port designated a "World Heritage in Danger" site on Wednesday by the UN cultural agency UNESCO, Russian missiles damaged energy facilities, authorities said, just as French Foreign Minister Catherine Colonna was arriving.

"What we saw today, new strikes on civilian Ukrainian infrastructure is not waging war, it's waging war crimes," she said.

The United States on Thursday formally designated Russian private military company the Wagner Group a transnational criminal organisation, freezing its US assets for helping Russia's military in Ukraine.

Since invading Ukraine on Feb 24 last year, Russia has shifted the focus of its rhetoric from "denazifying" and "demilitarising" its neighbour to confronting what it says is an aggressive and expansionist US-led NATO alliance.

Mykola Sunhurovskiy, director of military programmes at the Razumkov Centre think-tank in Kyiv, said Russia's war was turning into a protracted campaign that would require greater sacrifice by its people.

"It will require mobilisation of the economy and a move to new principles of mobilisation for the country's people," Sunhurovskiy said.

"This all means the war is entering a protracted phase and martial law will probably be declared in Russia."

Russia's invasion has killed thousands of civilians, uprooted millions and reduced cities to rubble.