A shelling in the center of the Russian border town of Belgorod on Saturday killed 21 people, including three children, local officials reported.

Another 110 people were injured in the attack, regional governor Vyacheslav Gladkov said, making it one of the deadliest attacks on Russian soil since Moscow’s invasion of Ukraine began 22 months ago.

Russian authorities accused Kiev of carrying out the attack, which came a day after an 18-hour airstrike on Ukraine that killed at least 41 civilians.

Images from Belgorod on social media showed burning cars and clouds of black smoke billowing between damaged buildings as air raid sirens sounded. One hit occurred near a public skating rink in the heart of the city, which is 25 miles (40 kilometers) north of the Ukrainian border and 415 miles (670 kilometers) south of Moscow. Although previous attacks hit the city, they rarely occurred in daylight and resulted in fewer deaths.

The Russian Defense Ministry said it had identified the munitions used in the attack as Czech-made Vampire missiles and Olkha missiles 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 the country’s health minister, Mikhail Murashko, had been instructed to join a delegation of medical personnel and rescue workers traveling from Moscow to Belgorod.

Russian diplomats also called for a UN Security Council meeting in connection with the attack. Speaking to Russia’s state news agency, Foreign Ministry spokeswoman Maria Zakharova said Britain and the United States were guilty of encouraging Kiev to carry out what she described as a “terrorist attack.” She also blamed EU countries for supplying Ukraine with weapons.

“Silence in response to the unbridled barbarism of the Ukrainian Nazis and their puppet masters and accomplices from ‘civilized democracies’ amounts to complicity in their bloody deeds,” the ministry said in a statement.

Early Saturday, Moscow officials reported that 32 Ukrainian drones were shot down over the country’s Moscow, Bryansk, Oryol and Kursk regions.

They also reported that two more people were killed in cross-border shelling in Russia. A man died and four other people were injured when a rocket hit a private house in the Belgorod region late Friday evening. A nine-year-old was killed in a separate incident in the Bryansk region.

Cities across western Russia have been regularly attacked by drones since May, with Russian officials blaming Kiev. Ukrainian officials never acknowledge responsibility for attacks on Russian territory or the Crimean peninsula. However, in the past, serious attacks on Ukrainian cities have been followed by major air strikes against Russia.

Russian drone strikes against Ukraine continued on Saturday. The General Staff of the Ukrainian Armed Forces reported that ten Iranian-made Shahed drones were shot down in the Kherson, Khmelnytskyi and Mykolaiv regions.

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

On Friday, Moscow forces fired 122 missiles and dozens of drones over Ukraine, an attack that an air force official described as the largest aerial bombardment of the war.

In addition to the 39 deaths, at least 160 people were injured and an unknown number were buried under rubble in the attack, which damaged a maternity hospital, apartment blocks and schools.

Western officials and analysts recently warned that Russia had limited its cruise missile attacks for months, apparently to stockpile for massive winter strikes in the hope of breaking the Ukrainians’ spirit.

Fighting on the front line has largely stalled due to winter weather after Ukraine’s summer counteroffensive failed to make a significant breakthrough along the roughly 1,000-kilometer (620-mile) contact line.

Russia’s ongoing airstrikes have also raised concerns among Ukraine’s neighbors.

Poland’s Defense Forces said on Friday that an unknown object had entered the country’s airspace before disappearing from radar and that all signs pointed to it being a Russian missile.

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

“We will not make any statements until we are presented with concrete evidence as these allegations are baseless,” he said.