Shelling in the center of the Russian border city of Belgorod Saturday killed 21 people, including three children, local officials reported.

A further 110 people were wounded in the strike, said regional governor Vyacheslav Gladkov, making it one of the deadliest attacks on Russian soil since the start of Moscow’s invasion of Ukraine 22 months ago.

Russian authorities accused Kyiv of carrying out the attack, which took place the day after an 18-hour aerial bombardment across Ukraine killed at least 41 civilians.

Images of Belgorod on social media showed burning cars and plumes of black smoke rising among damaged buildings as air raid sirens sounded. One strike hit close to a public ice rink in the very heart of the city, which lies 25 miles (40 kilometers) north of the Ukrainian border and 415 miles (670 kilometers) south of Moscow. While previous attacks have hit the city, they have rarely taken place in daylight and have claimed fewer lives.

Russia’s Defense Ministry said it identified the ammunition used in the strike as Czech-made Vampire rockets and Olkha missiles fitted with cluster-munition warheads. It provided no additional information, and The Associated Press was unable to verify its claims.

“This crime will not go unpunished,” the ministry said in a statement on social media.

The Kremlin said Russian President Vladimir Putin had been briefed on the situation, and that the country’s health minister, Mikhail Murashko, was ordered to join a delegation of medical personnel and rescue workers traveling to Belgorod from Moscow.

Russian diplomats also called for a meeting of the U.N. Security Council in connection with the strike. Speaking to Russia’s state news agency, Foreign Ministry spokeswoman Maria Zakharova said that Britain and the United States were guilty of encouraging Kyiv to carry out what she described as a “terrorist attack.” She also placed blame on EU countries who had supplied Ukraine with weapons.

“Silence in response to the unbridled barbarity of Ukraine’s Nazis and their puppeteers and accomplices from ‘civilized democracies’ will be akin to complicity in their bloody deeds,” the ministry said in a statement.

Earlier Saturday, Moscow officials reported shooting down 32 Ukrainian drones over the country’s Moscow, Bryansk, Oryol, and Kursk regions.

They also reported that cross-border shelling had killed two other people in Russia. A man died and four other people were wounded when a missile struck a private home in the Belgorod region late Friday evening and a 9-year-old was killed in a separate incident in the Bryansk region.

Cities across western Russia have come under regular attack from drones since May, with Russian officials blaming Kyiv. Ukrainian officials never acknowledge responsibility for attacks on Russian territory or the Crimean Peninsula. However, larger aerial strikes against Russia have previously followed heavy assaults on Ukrainian cities.

Russian drone strikes against Ukraine continued Saturday, with the General Staff of the Ukrainian Armed Forces reporting that 10 Iranian-made Shahed drones had been shot down across the Kherson, Khmelnytskyi, and Mykolaiv regions.

Local officials reported that three people had been killed by Russian missiles: a 55-year-old man in the Kherson region, a 43-year-old man in Stepnohirsk, a town in Ukraine’s Zaporizhzhia region, and a 32-year-old in the Chernihiv region.

On Friday, Moscow’s forces launched 122 missiles and dozens of drones across Ukraine, an onslaught described by one air force official as the biggest aerial barrage of the war.

As well as the 39 deaths, at least 160 people were wounded and an unknown number were buried under rubble in the assault, which damaged a maternity hospital, apartment blocks, and schools.

Western officials and analysts recently warned that Russia limited its cruise missile strikes for months in an apparent effort to build up stockpiles for massive strikes during the winter, hoping to break the Ukrainians’ spirit.

Fighting along the front line is largely bogged down by winter weather after Ukraine’s summer counteroffensive failed to make a significant breakthrough along the roughly 1,000-kilometer (620-mile) line of contact.

Russia’s ongoing aerial attacks have also sparked concern for Ukraine’s neighbors.

Poland’s defense forces said Friday that an unknown object had entered the country’s airspace before vanishing off radars, and that all indications pointed to it being a Russian missile.

Speaking to Russian state news agency RIA Novosti, Russia’s charge d’affaires in Poland, Andrei Ordash, said Saturday that Moscow would not comment on the event until Warsaw had given the Kremlin evidence of an airspace violation.

“We will not give any explanations until we are presented with concrete evidence because these accusations are unsubstantiated,” he said.