Russian strikes targeting energy infrastructure were reported across Ukraine on Thursday, as fighting for control of the eastern city of Bakhmut raged on.

For months Russia has been pummeling key facilities in Ukraine with missiles and drones, disrupting water, heating and electricity supplies for millions of people, AFP reported.

There were strikes reported on the capital Kyiv, the city of Kharkiv in the northeast and the southwestern region of Odessa, leading to widespread power cuts.

Kyiv mayor Vitali Klitschko said there had been “explosions” in the south of the city and about 15 percent of households were without power.

Ukrainian energy operator DTEK’s Kyiv division said that “due to an enemy attack, emergency power outages are in force”.

In the Kharkiv region, located on the border with Russia, governor Oleg Synegubov said there had been 15 strikes.

“The occupiers once again targeted critical infrastructure facilities,” he said on social media.

Synegubov added that information on victims and the scale of the damage was being “clarified”.

In the region’s main city of Kharkiv, mayor Igor Terekhov said “energy infrastructure” had been targeted and there were “problems” with electricity in some parts of the city.

In Odessa region, governor Maksym Marchenko said “missiles hit the energy infrastructure of the region as well as damaged residential buildings” following a “massive missile strike”.

“Fortunately, there were no casualties,” he said, adding that “power supply restrictions” were in place.

The wave of strikes comes after Russia reported making gains in the battle for the industrial city of Bakhmut, which has dragged on for months.

Russia’s Wagner mercenary group, which has spearheaded the attack on Bakhmut, claimed on Wednesday to have captured the eastern part of the city.

“What we see is that Russia is throwing more troops, more forces and what Russia lacks in quality they try to make up in quantity,” NATO Secretary General Jens Stoltenberg told reporters in Stockholm on the sidelines of an EU defense ministers meeting on Wednesday.

“We cannot rule out that Bakhmut may eventually fall in the coming days,” the head of the US-led military alliance said, adding that “this does not necessarily reflect any turning point of the war”.

Ukrainian officials have warned that the fall of Bakhmut could lead to further Russian advances in eastern Ukraine.

Ukrainian President Volodymyr Zelensky also on Wednesday hosted UN chief Antonio Guterres in Kyiv, who was on his third visit to Ukraine since Russia’s invasion.

Guterres stressed the need to extend a deal that has allowed Ukraine to export its grain but is due to expire.