DNIPRO, Ukraine (AP) — Ukrainian emergency crews on Monday sifted through what was left of a Dnipro apartment building destroyed by a Russian missile, placing bodies from one of the war’s deadliest single attacks in months in black bags and gingerly carrying them across steep piles of rubble.

Authorities said the death toll from Saturday’s strike rose to 40 and that 30 people remained missing Monday. Tall cranes swung across the jagged gaps in a row of residential towers, the engines growling as residents of one of Ukraine’s largest cities watched largely in silence under a gray sky.

About 1,700 people lived in the multistory building, and search and rescue crews have worked nonstop since the missile strike to locate victims and survivors in the wreckage. The regional administration said 39 people have been rescued and at least 75 were wounded.

The reported death toll put it among the deadliest attacks on Ukrainian civilians since before the summer, according to The Associated Press-Frontline War Crimes Watch project. Residents said the apartment tower did not house any military facilities.

Oleksander Anyskevych said he was in his apartment when the missile struck.

“Boom — and that’s it. We saw that we were alive and that’s all,” Anyskevych said Monday as he went to the site to see his wrecked apartment.

He told The Associated Press that he knew people who died under the rubble. One of his son’s classmates lost her parents.

Dnipro residents took flowers, candles and toys to the ruins.

“All of us could be in that place,” local resident Iryna Skrypnyk said.

The European Union’s foreign policy chief, Josep Borrell, called the strike, and others like it, “inhumane aggression” because it directly targeted civilians. “There will be no impunity for these crimes,” he said in a tweet Sunday.

United Nations Secretary-General Antonio Guterres strongly condemned the Dnipro strike, saying “attacks against civilians and civilian infrastructure violate international humanitarian law” and “must end immediately,” U.N. associate spokesperson Stephanie Tremblay said Monday.

Asked about the strike Monday, Kremlin spokesman Dmitry Peskov said the Russian military doesn’t target residential buildings and suggested the Dnipro building was hit as a result of Ukrainian air defense actions.

The strike on the building came amid a wider barrage of Russian cruise missiles across Ukraine. The Ukrainian military said Sunday that it did not have the means to intercept the type of Russian missile that hit the residential building in Dnipro.

Fierce fighting continued to rage Monday in Ukraine’s eastern Donetsk province, where military analysts have said both sides are likely suffering heavy troop casualties. No independent verification of developments was possible.

Donetsk and neighboring Luhansk province make up the Donbas, an expansive industrial region bordering Russia that Russian President Vladimir Putin identified as a focus from the war’s outset. Moscow-backed separatists have been fighting Kyiv’s forces there since 2014.

The Russian and Belarusian air forces began a joint exercise Monday in Belarus, which borders Ukraine and served as a staging ground for Russia’s Feb. 24 invasion of Ukraine.The drills are set to run through Feb. 1, the Belarusian Defense Ministry said. Russia has sent its warplanes to Belarus for the drills.

The Institute for the Study of War, a Washington think tank, reported signs of the Kremlin taking steps to turn its Ukraine invasion into “a major conventional war” after months of embarrassing military reversals.

What Moscow calls “a special military operation” aimed to capture the Ukrainian capital, Kyiv, within weeks and to install a Kremlin-friendly regime there, but Russian forces ultimately withdrew from around Kyiv, the think tank said. Then came a successful Ukrainian counteroffensive in recent months before the onset of winter slowed military advances.

“The Kremlin is likely preparing to conduct a decisive strategic action in the next six months intended to regain the initiative and end Ukraine’s current string of operational successes,” the Institute for the Study of War said in a report late Sunday.

It noted reports indicating the Russian military command was in “serious preparations” for an expanded mobilization effort, conserving mobilized personnel for future use, while seeking to boost military industrial production and reshuffling its command structure.

That means Ukraine’s Western allies “will need to continue supporting Ukraine in the long run,” the think tank said.

NATO member nations have sought in recent days to reassure Ukraine that they will stay the course. The United Kingdom has pledged tanks and the U.S. military’s new, expanded combat training of Ukrainian forces began in Germany on Sunday.

Poland’s prime minister urged the German government to supply a wide range of weapons to Kyiv and voiced hope that Berlin would soon approve a transfer of battle tanks.

Other developments on Monday:

— Russian forces shelled the city of Kherson and the Kherson region, killing three people and wounding 14 others over the last 24 hours, regional Gov. Yaroslav Yanushevych said. In the city of Kherson, the shelling damaged a hospital, a children disability center, a shipyard, critical infrastructure and apartment buildings.

— Russian forces struck the city of Zaporizhzhia, damaging industrial infrastructure and wounding five people, two of them children, the deputy head of Ukraine’s presidential office Kyrylo Tymoshenko reported.

— Russian air defenses downed 10 drones Monday over the Black Sea near the port of Sevastopol in annexed Crimea, Mikhail Razvozhayev, the Russian-installed head of Sevastopol, reported.