Russian forces resumed scattered attacks on Kyiv, western Ukraine and beyond Saturday in an explosive reminder to Ukrainians and their Western supporters that the whole country remains under threat despite Russia’s pivot toward mounting a new offensive in the east.

Stung by the loss of its Black Sea flagship and indignant over alleged Ukrainian aggression on Russian territory, Russia’s military command had warned a day earlier of renewed missile strikes on Ukraine’s capital. Officials in Moscow said they were targeting military sites.

But the toll of war reaches much deeper. Each day brings new discoveries of civilian victims of a war that has shattered European security and plunged East-West relations to new lows. In the Kyiv region alone, Ukrainian authorities have reported finding the bodies of more than 900 civilians, most shot dead, since Russian troops retreated two weeks ago.

Russia’s preparations for the anticipated eastern offensive are producing more victims, A mother wept over her 15-year-old son’s body in the partially blockaded city of Kharkiv, where shelling increased this week. Nine civilians died and more than 50 people were wounded on Friday, the president’s office reported.

An explosion believed to be caused by a missile struck Saturday near an outdoor market in Kharkiv, Ukraine’s second-largest city, according to firefighters and AP journalists at the scene. One person was killed, and at least 18 people were wounded, according to rescue workers.

In the capital, smoke rose early Saturday from eastern Kyiv as Mayor Vitali Klitschko reported a strike on the the city’s Darnytski district. One person was killed and several more were wounded, he said. The mayor advised residents who fled the city earlier in the war not to return for their safety.

“Our air defense forces are doing everything they can to protect us, but the enemy is insidious and ruthless,” Klitschko said.

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It was not immediately clear from the ground what was hit in the attack. Darnytskyi is a sprawling district on the southeastern edge of the capital, containing a mixture of Soviet-style apartment blocks, newer shopping centers and big-box retail outlets, industrial areas and railyards.

Earlier this week the Russian military said it would carry out strikes on Kyiv, and Russian Defense Ministry spokesman Igor Konashenkov said Saturday an armored vehicle plant in the Ukrainian capital was targeted. He didn’t specify where the plant is located, but there is one in the Darnytskyi district.

He said it was among multiple Ukrainian military sites hit with “air-launched high-precision long-range weapons.” As the U.S. and Europe send new arms to Ukraine, the strategy could be aimed at hobbling Ukraine’s defenses ahead of what’s expected to be a full-scale Russian assault in the east.

It was the second strike in the Kyiv area in two days. Another hit a missile plant on Friday as tentative signs of prewar life began to resurface in the capital after Russian troops failed to capture the city and withdrew to concentrate on lauching a full-scale assault in eastern Ukraine.

Kyiv was not the only target far from the eastern front Saturday. The governor of the Lviv region in western Ukraine – an area long seen as a safe zone – reported airstrikes on the region by Russian Su-35 aircraft that took off from neighboring Belarus. Gov. Maksym Kozytskyy didn’t provide details about possible casualties or damage.

Fighting continued in the pummeled southern port city of Mariupol, where Russian forces have maintained a blockade since the early days of the invasion, and dwindling numbers of Ukrainian defenders have held out against the siege.

Mariupol’s capture would allow Russian forces in the south, which came up through the annexed Crimean Peninsula, to fully link up with troops in the Donbas region, Ukraine’s eastern industrial heartland.

The battle for control of the city has come at a horrific cost to trapped and starving civilians. Locals reported seeing Russian troops digging up bodies from residential courtyards and prohibiting new burials.

“Why the exhumation is being carried out and where the bodies will be taken is unknown,” the city council said Friday on the Telegram messaging app.

The mayor said this week that the city’s death toll could surpass 20,000. Other Ukrainian officials have said they expect to find evidence in Mariupol of atrocities like the ones discovered in Bucha and other towns outside Kyiv.

Ukrainian President Volodymyr Zelenskyy accused Russian troops occupying parts of the Kherson and Zaporizhzhia regions in the south of terrorizing civilians and hunting for anyone who served in Ukraine’s military or government.

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“The occupiers think this will make it easier for them to control this territory. But they are very wrong. They are fooling themselves,” Zelenskyy said in his nightly video address. “Russia’s problem is that it is not accepted — and never will be accepted — by the entire Ukrainian people. Russia has lost Ukraine forever.”

He also warned in an interview with CNN that “all of the countries of the world” should be prepared for the possibility that Russian President Vladimir Putin could use tactical nuclear weapons in the war, an underlying fear ever since Putin launched it Feb. 24.

Zelenskyy estimated that 2,500 to 3,000 Ukrainian troops have died in the war, and about 10,000 have been injured.

The Russians were holding captive some 700 Ukrainian troops and more than 1,000 civilians, Ukrainian Deputy Prime Minister Iryna Vereshchuk said in televised remarks on Saturday. Vereshchuk said Ukraine holds about the same number of Russian troops as prisoners and - intends to arrange a swap with Moscow but is demanding the release of civilians “without any conditions.”

Russia’s warning of stepped-up attacks on the capital came after Russian authorities accused Ukraine on Thursday of wounding seven people and damaging about 100 residential buildings with airstrikes in Bryansk, a region bordering Ukraine.

Ukrainian officials have not confirmed striking targets in Russia, and the reports could not be independently verified.

However, Ukrainian officials did strike a key Russian warship with missiles earlier this week, in an important victory for Ukraine and symbolic defeat for Russia.

The Moskva, named for the Russian capital, sank while being towed to port Thursday after taking heavy damage. Moscow did not acknowledge any attack, saying only that a fire had detonated ammunition on board.

The sinking reduces Russia’s firepower in the Black Sea and seemed to symbolize Moscow’s fortunes in an eight-week invasion widely seen as a historic blunder following the Russian retreat from the Kyiv region and much of northern Ukraine.

After the withdrawal, bodies were abandoned in the streets of towns around Kyiv or given temporary burials. Andriy Nebytov, who heads the region’s police force, cited police data indicating 95% died from gunshot wounds.

“Consequently, we understand that under the (Russian) occupation, people were simply executed in the streets,” Nebytov said.

More bodies are being found every day under rubble and in mass graves, he added, with the largest number found in Bucha, more than 350. According to Nebytov, utility workers gathered and buried bodies in the Kyiv suburb while it remained under Russian control. Russian troops, he added, had been “tracking down” people who expressed strong pro-Ukrainian views.

It’s not certain when Russia will launch a full-scale campaign.

The diplomatic chasm between Russia and the West deepened further Saturday, as Moscow barred British Prime Minister Boris Johnson and a dozen other top U.K. officials from entering the country in response to British sanctions.