At least 11 Russian soldiers were killed Saturday in a shooting incident that underlined the challenges posed by Russian President Vladimir Putin’s hasty mobilization, just as Ukrainian troops pressed an offensive to reclaim the areas in the country’s south that were illegally annexed by Moscow.

The Russian Defense Ministry said two men opened fire at volunteer soldiers during a target practice session in western Russia, killing 11 of them and wounding 15 others before being killed themselves. The ministry called it a terror attack.

Russia has lost ground in the nearly seven weeks since Ukraine’s armed forces opened their southern counteroffensive. This week, the Kremlin launched what is believed to be its largest coordinated air and missile raids on Ukraine’s key infrastructure since Russia’s invasion of Ukraine on Feb. 24.

In the continuation of those attacks, a missile strike Saturday seriously damaged a key energy facility in Ukraine’s capital region, the country’s grid operator said. Following mounting setbacks, the Russian military has worked to cut off power and water in far-flung populated areas while also fending off Ukrainian counterattacks in occupied areas.

In the Zaporizhzhia region, Gov. Oleksandr Starukh said the Russian military carried out strikes with suicide drones from Iran and long-range S-300 missiles. Some experts said the Russian military’s use of the surface-to-air missiles may reflect shortages of dedicated precision weapons for hitting ground targets.

Dmytro Pocishchuk, a hospital medic in the Zaporizhzhia region’s capital who has treated dozens of people wounded during Russian attacks in recent weeks, said people sought safety outdoors or in his building’s basement when the familiar blasts started at 5:15 a.m. Saturday.

“If Ukraine stops, these bombings and killings will continue. We can’t give up to the Russian Federation,’” Pocishchuk said several hours later. He put a small Ukrainian flag on the broken windshield of his heavily damaged car.

Kyiv region Gov. Oleksiy Kuleba said the missile that hit a power facility Saturday morning didn’t kill or wound anyone. Citing security, Ukrainian officials didn’t identify the site, one of many infrastructure targets the Russian military tried to destroy after an Oct. 8 truck bomb explosion damaged the bridge that links Russia to the annexed Crimean Peninsula.

Ukrainian electricity transmission company Ukrenergo said repair crews were working to restore electricity service, but warned residents about further possible outages. Kyrylo Tymoshenko, the deputy head of the Ukrainian president’s office, urged residents of the capital and three neighboring regions to conserve energy.

“Putin may hope that by increasing the misery of the Ukrainian people, President (Volodymyr) Zelenskyy may be more inclined to negotiate a settlement that allows Russia to retain some stolen territory in the east or Crimea,” said Ian Williams, a fellow at the Center for Strategic and International Studies, a policy organization based in Washington. “A quick look at history shows that the strategic bombing of civilians is an ineffective way to achieve a political aim. ”

This week’s wide-ranging retaliatory attacks, which included the use of self-destructing explosive drones from Iran, killed dozens of people. The strikes hit residential buildings as well as infrastructure such as power stations in Kyiv, Lviv in western Ukraine, and other cities that had seen comparatively few strikes in recent months.

Putin said Friday that Moscow didn’t see a need for additional massive strikes but his military would continue selective ones. He said that of 29 targets the Russian military planned to knock out in this week’s attacks, seven weren’t damaged and would be taken out gradually.

The Institute for the Study of War, a think tank based in Washington, interpreted Putin’s remarks as intended to counter criticism from pro-war Russian bloggers who “largely praised the resumption of strikes against Ukrainian cities, but warned that a short campaign would be ineffective.”

In the southern Kherson region, one of the first areas of Ukraine to fall to Russia after the invasion and which Putin also illegally designated as Russian territory last month, Ukrainian forces pressed their counteroffensive Saturday.

Kyiv’s army has reported recapturing 75 villages and towns there in the last month, but said the momentum had slowed, with the fighting settling into the sort of grueling back-and-forth that characterized Russia’s months-long offensive to conquer Ukraine’s eastern Donbas region.

On Saturday, Ukrainian troops attempted to advance south along the banks of the Dnieper River toward the regional capital, also named Kherson, but didn’t gain any ground, according to Kirill Stremousov, a deputy head of the occupied region’s Moscow-installed administration.

“The defense lines worked, and the situation has remained under the full control of the Russian army,” he wrote on his messaging app channel.

The Kremlin-backed local leaders asked civilians Thursday to leave the region to ensure their safety and to give Russian troops more maneuverability. Stremousov reminded them they could evacuate to Crimea and cities in southwestern Russia, where Moscow offered free accommodations to residents who agreed to leave.

Maj. Gen. Igor Konashenkov, the Russian Defense Ministry’s spokesman, said the military destroyed five crossings on the Inhulets River, another route Ukraine’s fighters could take to progress toward the Kherson region.

Konashenkov claimed Russian troops also blocked Ukrainian attempts to make inroads in breaching Russian defenses near Lyman, a city in the annexed Donetsk region of eastern Ukraine that the Ukrainians retook two weeks ago in a significant defeat for the Kremlin.

Amid the fighting, two men from an unnamed former Soviet nation fired on volunteer soldiers during target practice at a firing range in the Belgorod region that borders Ukraine and were killed by return fire, the Russian Defense Ministry said.

The shooting comes amid a mobilization ordered by Putin to beef up Russian forces in Ukraine — a hasty and poorly executed move that triggered protests and caused hundreds of thousands to flee Russia. Some of the mobilized reservists were sent to the front lines without receving proper training and equipment, according to activists and media reports.

Putin said on Friday that more than 220,000 reservists already had been called up as part of an effort to recruit 300,000.

To the north and east of Kherson, Russian shelling killed two civilians in the Dnipropetrovsk region, Gov. Valentyn Resnichenko said. He said the shelling of the city of Nikopol, which is located across the Dnieper from the Russian-occupied Zaporizhzhia Nuclear Power Plant, damaged a dozen residential buildings, several stores and a transportation facility.

Fighting near the nuclear plant, Europe’s largest, has been an ongoing concern during the nearly eight-month war. The power station temporarily lost its last remaining outside electricity source twice in the past week, fueling fears the reactors could eventually overheat and cause a catastrophic radiation leak.

International Atomic Energy Agency Director-General Rafael Grossi reported that such fears were somewhat eased late Friday, because Ukrainian engineers had managed after several weeks to restore backup power lines that can serve as a “buffer” in case of further war-related outages.

“Working in very challenging conditions, operating staff at the Zaporizhzhia Nuclear Power Plant are doing everything they can to bolster its fragile offsite power situation,” Grossi said. “Restoring the backup power connection is a positive step in this regard, even though the overall nuclear safety and security situation remains precarious.”

(AP)