Russian forces shelled Ukrainian cities on Sunday amid a major effort to seize more land in the country’s east, and officials in Kyiv said Moscow is having trouble launching its long-awaited full-scale offensive there.

One person was killed and another wounded on Sunday morning by shelling of Nikopol, a city in the southeastern region of Dnipropetrovsk, Governor Serhii Lysak said. The shelling damaged four residential buildings, a vocational school and a water treatment plant.

In Kharkiv, Ukraine’s second-largest city, one person was injured after three Russian S-300 missiles hit infrastructure facilities overnight, regional governor Oleh Syniehubov said.

Ukrainian forces also shot down five drones, four Shahed killer drones and one Orlan-10 reconnaissance drone, over the partially occupied Zaporizhzhia and Donetsk regions on Saturday night, the Kyiv army reported.

The attacks come as Russian forces push to seize more land in Donbas’ eastern industrial heartland, made up of the Donetsk and Lugansk regions. Ukrainian and Western officials have warned that Russia could launch a broad new offensive there to try to turn the tide of the conflict as the war nears the one-year mark.

A man holds the flag of a volunteer medical battalion helping to evacuate wounded Ukrainian servicemen in the Donetsk region.YASUYOSHI CHIBA / AFP – Getty Images

But Ukrainian officials say Moscow is having trouble mounting such an offensive.

“They are having big problems with a big offensive,” Oleksiy Danilov, secretary of Ukraine’s National Security and Defense Council, told Ukrainian television on Saturday night.

“They have started their offensive, they just don’t say they have, and our troops are repelling it very strongly. The offensive they planned is already slowly underway. But (it’s not) the offense they were counting on,” Danilov said.

A US-based think tank pointed out that it is also Russia’s pro-Kremlin military bloggers who are questioning Moscow’s ability to launch a broad offensive in Ukraine. They «continue to appear demoralized by the Kremlin’s prospects of launching a major offensive,» the Institute for the Study of War said in its latest report.

Earlier this week, the owner of the Russian private military contractor Wagner Group, which is actively involved in the fighting in Ukraine, said the war could drag on for years.

The group’s founder, Yevgeny Prigozhin, said in a video interview released late Friday that it could take Russia anywhere from 18 months to two years to secure full control of Donbass. He added that the war could last three years if Moscow decides to capture wider territories east of the Dnieper river.

The statement by Prigozhin, a millionaire who has close ties to Russian President Vladimir Putin and was nicknamed «Putin’s chef» for his lucrative Kremlin catering deals, was an acknowledgment of the difficulties the Kremlin has faced in the campaign , which he initially hoped to conclude in a few weeks when Russian troops invaded Ukraine on February 24.

Russia suffered a series of humiliating setbacks in the fall as the Ukrainian military launched successful counteroffensives to retake wide swaths of territory in the east and south.

On Sunday, Prigozhin said Wagner’s fighters seized the Krasna Hora settlement north of Bakhmut, a strategic town at the epicenter of fighting in recent months.