Russia has launched a new barrage of missiles at targets across Ukraine, killing at least 12 people in the eastern-central city of Dnipro and disrupting power supplies in the Kyiv and Kharkiv regions, officials said.

The attacks on Saturday smashed a nine-storey apartment block in Dnipro, reducing an entire section of the building to rubble and sending smoke billowing into the sky. The deaths included that of a 15-year-old girl, according to officials.

Some 64 others were also wounded.

“Tragedy!” said Borys Filatov, mayor of the rocket-making city on the Dnieper River.

“I’ve gone to the site. … We will be going through the rubble all night.”

Pictures from the scene showed firefighters putting out a blaze around the carcasses of some cars in Dnipro. A broad chunk of the apartment block was missing, while the exterior of the rest of the building was badly damaged.

Trapped residents were signalling their location under the debris with their mobile phone torches, according to Ukrainian media reports.

“They keep sending SMS-es,” Mikhailo Lysenko, deputy mayor of Dnipro said in a social media video. “We stop our work now and then to keep silence and we hear people scream from underneath the rubble.”

Regional governor Valentyn Reznichenko said seven children were among the wounded, the youngest three years old.

“The fate of 26 people is still unknown,” he added.

Ukrainian President Volodymyr Zelenskyy said it was not yet known how many were under the rubble.

“Unfortunately, the death toll is growing every hour,” he said in his nightly address.

Besides Dnipro, other cities hit on Saturday included Odesa in the south, Kharkiv in the east, Lviv in the west and the Ukrainian capital, Kyiv. Civilian infrastructure, including electricity sites, were once again damaged and power outages were reported.

Emergency blackouts were applied in “most regions” of Ukraine on Saturday due to the raids, Energy Minister German Galushchenko said.

He warned that the coming days would be “difficult”.

Officials said the Kharkiv region lost power completely and that disruptions to electricity and water supplies in Lviv were also possible.

Russia has been targeting Ukraine’s energy infrastructure with missiles and drones since October, causing sweeping blackouts and disruptions to central heating and running water.

Military top commander Valerii Zaluzhny said that Russia fired 33 cruise missiles overall on Saturday, of which 21 were shot down.

UK pledges tanks

Moldova, Ukraine’s southwestern neighbour, said it had found missile debris on its territory after the latest Russian raids.

“Russia’s brutal war against Ukraine directly impacts Moldova again,” President Maia Sandu tweeted, posting photos of the wreckage.

“We strongly condemn today’s intensified attacks.”

In his nightly speech, Zelenskyy appealed to the West to supply more weapons to prevent further deaths from what he described as “Russian terror”.

“What’s needed for this? The kind of weapons that our partners have in stockpiles and that our warriors have come to expect. The whole world knows what and how to stop those who are sowing death,” he said.

Saturday’s attack comes as Western powers consider sending heavy weaponry to Kyiv and ahead of a meeting of Ukraine’s allies in Ramstein in Germany next Friday, where governments will announce their latest pledges of military support.

The United Kingdom on Saturday became the first Western country to pledge heavy tanks for the war effort, with British Prime Minister Rishi Sunak saying his country will send 14 Challenger 2 tanks to Ukraine.

Sunak’s office said the British prime minister believed that a “long and static war only serves Russia’s interests”.

“UK defence and security officials believe a window has opened up where Russia is on the backfoot due to resupply issues and plummeting morale,” the statement said. “The Prime Minister is therefore encouraging allies to deploy their planned support for 2023 as soon as possible to have maximum impact.”

Saturday’s attacks came as Ukrainian and Russian forces battled for control of Soledar, a small salt-mining town in eastern Ukraine that for days has been the focus of a relentless Russian assault.

Capturing Soledar, which had a pre-war population of 10,000, could improve the position of Russian forces as they push towards what has been their main target since October, the nearby transport crossroads of Bakhmut.

Russia said on Friday that its forces had taken control of the town, but Ukraine has denied the claim.

Al Jazeera’s Charles Stratford, reporting from near Soledar, said there was no obvious sign of a Ukrainian withdrawal from the town.

“Russia says it’s taken full control of Soledar, but the smoke rising from impact sites, the explosions from almost constant artillery and heavy machine gun fire suggests otherwise,” he said.

On streets leading to Soledar, army medics were waiting at intervals to take the wounded to hospitals away from the front line, said Stratford. Ukrainian armoured personnel carriers were seen carrying troops towards the town, while the tree lines were packed with artillery in defensive positions.

One soldier appealed for better weapons.

“It will be hard for us to push them back,” he told Al Jazeera. “We will suffer big losses. They move in such great numbers that sometimes our old guns overheat as we try to shoot as many as we can.”

Turkey said Saturday it was ready to push for local ceasefires in Ukraine and warned that neither Moscow nor Kyiv had the military means to “win the war”.

President Recep Tayyip Erdogan’s foreign policy adviser, Ibrahim Kalin, conceded that it seemed unlikely that the warring sides were ready to strike an “overarching peace deal” in the coming months.