KYIV, Ukraine — Explosions far behind the front lines shook Ukraine on Friday, as a Russian missile demolished part of a hospital complex and apparent Ukrainian strikes hit Russian-occupied cities, in their escalating, long-range aerial war.
The attack on a medical center in the central city of Dnipro killed at least two people, left three more missing and injured at least 30, Ukrainian officials said. It destroyed a three-story building and damaged several others.
President Volodymyr Zelensky of Ukraine posted to social media a video of a gutted building, its roof and upper walls missing, belching smoke into the sky, calling it “another crime against humanity.”
Ukraine is expected to launch a major counteroffensive soon — some analysts say it may already be in its earliest phases — and both sides have stepped up their strikes from a distance ahead of the clash on the ground. Kyiv’s forces have increased the tempo and range of attacks deep into Russian-held territory, primarily on military depots, convoys and troop concentrations, and railroads used by Russian forces.
On Friday, explosions were reported over the Russian-occupied southern city of Berdyansk, about 60 miles from the front, for the second time this week. Vladimir Rogov, a Russian occupation official in southern Ukraine, said that several loud explosions had echoed across Berdyansk overnight and that Russian air defenses thwarted a Ukrainian attack, a claim that could not be confirmed.
The Ukrainian military did not comment on Berdyansk specifically but said its air force had “delivered five strikes targeting enemy manpower and equipment clusters.” GeoConfirmed, one of several volunteer groups that closely track battlefield movements in Ukraine, posted images on Twitter showing a large fire and said impacts had been recorded in Berdyansk, though it was unclear what was hit.
On Friday night, there were two large explosions in another occupied southern city, Mariupol, about 40 miles from Berdyansk, near the Azovstal steel works, according to Mariupol city government officials who fled before the Russians took over. Russian occupation officials said the blasts were caused by Ukrainian missiles, newly supplied by Britain, according to the state news agency Tass.
The hospital strike on Dnipro on Friday morning followed one of Russia’s increasingly frequent overnight barrages aimed at cities and infrastructure far from the battlefield, with missiles and drones fired in bunches in an attempt to overwhelm Ukrainian air defenses. Ukraine’s military said it had destroyed 10 of the 17 missiles that were launched, and 23 of 31 attack drones.
“Only an evil state can fight against clinics,” Mr. Zelensky wrote on Twitter. “There can be no military purpose in this. It is pure terror.”
Russia’s defense ministry told state media that it had struck Ukrainian ammunition depots.
The city of Dnipro is a hub for Ukrainian soldiers wounded in battle, usually a first stop before they are transported to hospitals in other parts of the country. It was not clear if any Ukrainian soldiers were being treated at the facility that was hit on Friday.
“It was a really difficult night,” said Serhii Lysak, head of the Dnipro regional government. One of the people killed, he said, was a 69-year-old man who was “just passing by” when the hospital was hit.
From the start of President Vladimir V. Putin’s full-scale invasion 15 months ago, Russia has used its advantage in weaponry to bombard civilian targets throughout Ukraine, like hospitals, schools and power plants, which is considered a war crime. At first the long-range strikes were entirely one-sided and largely unimpeded.
But as Ukraine’s military has gained experience and obtained a growing array of Western weapons, it has become more adept at intercepting such Russian attacks, and more capable of responding in kind.
Last summer, the United States began supplying Ukraine with HIMARS rocket artillery systems with a range of about 50 miles, which made a crucial difference in battle. In December, Ukraine showed that it could adapt Soviet-era surveillance drones into long-range weapons to strike within Russia. And Britain this month began giving Ukraine high-precision, air-launched Storm Shadow cruise missiles with a range of about 150 miles — far enough to reach any corner of Russian-occupied Ukraine.
After a strike on Berdyansk on Sunday, local Russian officials claimed that Kyiv had used the newly acquired Storm Shadow.
Russian forces have turned Berdyansk, a port on the Sea of Azov, into a military stronghold, using it as a base for soldiers and a transit point for supplies, according to military analysts.
Closer to the front lines in the Donetsk region, Russian forces breached a dam on the Vovcha River on Thursday, causing flooding downstream that threatened six villages, home to almost 1,000 people, Pavlo Kyrylenko, the Ukrainian regional administrator, said on Friday. The strike may have been a bid to impede Ukrainian troop movements behind the lines, a tactic both sides have used in this war.
Ukraine’s government has repeatedly warned of the risk that Russia will blow up the much larger Kakhovka dam on the Dnipro River, inundating a far wider area and lowering the reservoir that cools the Zaporizhzhia Nuclear Power Plant, creating an emergency there.
Late on Friday, Ukrainian military intelligence warned that the Russians planned to create an emergency at the power plant, which they occupy, “in the next few hours” to provide a pretext for a cease-fire that would forestall the counteroffensive. The Ukrainian government has issued warnings before about threats to the plant, but has rarely been so specific.
“A strike will be carried out” on the plant, followed by the announcement of a radioactive leak, the intelligence department said on Telegram, adding that the Russians would blame Ukraine. Energoatom, the Ukrainian nuclear power company, repeated the allegation.
The Ukrainians offered no evidence for the claim, leaving it unclear if it might be a case of disinformation intended to keep the Russians off balance. Hours later, a Russian occupation official claimed that it was the Ukrainians who were planning to create an emergency at the plant.
The United States is monitoring the situation closely but has seen no information to support the idea that an incident is planned, said an American official who spoke on the condition of anonymity to discuss intelligence matters. The United States has direct access to data from radiation sensors in the area, the official said.
The United Nations’ International Atomic Energy Agency has inspectors based at the Zaporizhzhia plant, and a rotation of some arriving and others leaving was supposed to take place on Friday. The Ukrainians said the Russians disrupted it. The Russian state energy company now overseeing the plant told Tass that the Ukrainians had blocked it.
The U.N. agency declined to comment.
On the diplomatic front, Pope Francis, who has offered the Vatican as a mediator, refused to endorse the position of Ukraine and many of its Western backers, that Russia must return all the Ukrainian territory it has seized. Kyiv has called that a prerequisite for peace talks, insisting that otherwise, any cease-fire would simply solidify Russian gains.
In an interview on Thursday, in Spanish, with the Telemundo network, Francis was asked twice whether Russia should relinquish the territory. The first time, he did not answer the question directly.
“It’s a political issue,” he said the second time. “Peace will be achieved once they can talk to each other.”
Andrew E. Kramer and Maria Varenikova contributed reporting from Pokrovsk, Ukraine, and Julian E. Barnes from Washington.