Shelling killed at least 28 people and injured 30, including two children, near a market in the Russian-controlled city of Donetsk in eastern Ukraine on Sunday, according to Russian officials. Moscow blamed Ukraine for the attack, while Kyiv denied responsibility.

The Russian Foreign Ministry said in a statement that a market and shops in the city’s Kirovsky district were targeted with multiple launch rocket systems, with the shelling reportedly coming from the direction of Avdiivka. Kyiv “once again committed a barbaric terrorist act against the civilian population of Russia,” the Russian ministry said. “There are a large number of victims.”

CNN is unable to independently verify this claim.

Ukraine’s armed forces said they were not responsible for the shelling attacks. “The Russians are spreading [mis-]information about the strike on a market in Donetsk. We responsibly declare that the forces under the control of the Tavria military formation did not engage in combat operations in this case,” a statement on the Facebook page of the armed forces’ Tavria command said.

“Russia must be held accountable for the lives of the Ukrainians taken,” it added.

Russia has responded with outrage to previous Ukrainian attacks but has been responsible for thousands of civilians deaths following its full-scale invasion of Ukraine.

Russia’s Investigative Committee has launched an investigation and “all those involved and responsible for this and other terrorist attacks on our soil will suffer inevitable punishment,” the ministry said.

Denis Pushilin, the head of the self-proclaimed Donetsk People’s Republic, said that the attack came on the busiest day of the week for the area and that search teams were looking for fragments of weapons.

At least 27 civilians were killed and at least 25 were injured in the area of a market and shops in the Kirovsky district of the city of Donetsk, Pushilin said in a Telegram post.

Another man was also killed on Sunday in another part of Donetsk city as a result of shelling, Pushilin said. Five additional people were wounded in the city and elsewhere in Russian-occupied parts of the region on Sunday, he said.

Residential buildings, a school and shops in different Russian-occupied parts of the region were also damaged, he said.

UN Secretary-General António Guterres condemned the deadly attacks on Russian-controlled parts of Donetsk region, a UN spokesperson said on Sunday.

“The Secretary-General strongly condemns all attacks against civilians and civilian infrastructure, including today’s shelling of the city of Donetsk in Ukraine,” the spokesperson said in a statement.

“Attacks against civilians and civilian infrastructure are prohibited under international humanitarian law, are unacceptable and must stop immediately,” the statement continued.

Static frontlines of war

Donetsk is one of four Ukrainian regions that Moscow said in 2022 it would recognize as Russian territory – an annexation process which is illegal under international law.

The region, which is partially but not fully controlled by Russian forces, is on the frontline of fighting in the east.

The Donetsk attack comes with the frontlines of the war largely static.

Ukraine’s counteroffensive failed to deliver major gains and its troops are now under pressure from Russia at several points along the 1,000 kilometer-long frontline.

Kyiv’s troops have withdrawn from the village of Krokhmalne in the northeast of the country, close to the border between Kharkiv and Luhansk regions – with an army spokesman saying on Ukrainian TV that its troops’ position have been moved to “where it is more advantageous for them to destroy the enemy.”

In another indication of increasing Russian pressure, Ukraine’s military says it expects to see Russia’s forces step up operations around the embattled town of Avdiivka, as well as nearby Nevelske and Pervomaiske – which all lie to the immediate northwest of Donetsk city.

“The enemy is regrouping, and we are preparing for an increase in their activity,” a Ukrainian army spokesperson said.

In recent months, Avdiivka has become a focus of Russia’s fight, in much the same way that Bakhmut was in the first half of 2023. The Ukrainian army spokesman said Russia now had about 40,000 Russian personnel in the area.