Ukraine Works to Restore Electricity After Russian Missile Barrage

The recent attacks, which have damaged nearly a third of the country’s energy infrastructure, seek to undermine Ukrainians’ will to fight and provoke a humanitarian crisis, according to officials in Kyiv.

There were power outages in more than 10 regions of Ukraine as a result of Saturday’s attack, which energy-grid operator Ukrenergo said was one of the most destructive to date.

In his nightly address, President Volodymyr Zelensky said Ukrainians wouldn’t be deterred. “Russian propagandists are lying when they say that this terror against our infrastructure and people can somehow slow down the active actions of our military,” he said.

Russian Defense Minister Sergei Shoigu spoke by phone to his U.S., French, Turkish and U.K. counterparts, raising new warnings about the war.

Mr. Shoigu told the French defense minister that the situation in Ukraine is trending toward “further uncontrolled escalation,” according to the Russian Defense Ministry. Mr. Shoigu, the ministry said, also warned about Ukraine’s possible use of a dirty bomb, which combines conventional explosives with radioactive materials.

Ukraine’s Foreign Minister Dmytro Kuleba dismissed the allegation as dangerous and absurd. “Russians often accuse others of what they plan themselves,” he said on Twitter.

Commenting on Mr. Shoigu’s reported remarks, Mr. Zelensky said: “If Russia has prepared another round of raising stakes and another escalating step, it must see now, preemptively…that the world will not swallow that.”

An account of the conversation from the French Defense Ministry said Mr. Shoigu warned of Ukraine setting off a dirty bomb on their territory to make it seem like Russia was responsible for the act. The French defense minister warned against any nuclear escalation, calling on Russia to do everything possible to de-escalate, according to the account.

U.K. Defense Secretary Ben Wallace refuted Russian allegations that Ukraine was planning “actions” facilitated by Western countries, including the U.K., to escalate the conflict.

Mr. Shoigu’s call with U.S. Defense Secretary Lloyd Austin was the second such call in a week. Russia initiated the call, a U.S. official said, and the two officials spoke for less than a half-hour.

“Secretary Austin rejected any pretext for Russian escalation and reaffirmed the value of continued communication amid Russia’s unlawful and unjustified war against Ukraine,” a Pentagon spokesman said.

Late Sunday, the U.S., U.K. and France released a joint statement on Mr. Shoigu’s remarks.

“Our countries made clear that we all reject Russia’s transparently false allegations that Ukraine is preparing to use a dirty bomb on its own territory,” the statement said. “The world would see through any attempt to use this allegation as a pretext for escalation.”

Several cities in Ukraine’s western Volyn region bordering Poland remained without power on Sunday, authorities said. Electricity supply in the western Khmelnytski region was largely restored, according to authorities.

Ukraine has urged residents to limit their electricity use to reduce pressure on the grid, while calling on Western partners to expedite the delivery of weapons systems to protect its skies.

Sixteen Iranian-made drones were shot down by Ukrainian air defense overnight, according to the country’s air-force command, including 11 over the southern port city of Mykolaiv. The mayor of Mykolaiv, Oleksandr Sinkevych, said five missiles landed in the city overnight, with one striking a residential building. There were no casualties, he said.

The recent shift toward targeting Ukrainian infrastructure with cruise missiles and drones comes as Russian forces struggle on the battlefield, prompting criticism of Moscow’s approach to the war.

Rhetoric has also hardened, with Russian nationalists celebrating attacks on Ukrainian infrastructure and calling for more.

After months of strikes against Russian supply lines in the occupied Kherson region, Kyiv’s strategy of squeezing the invading forces is gradually taking effect.

Ukraine’s armed forces on Saturday said Russian troops had abandoned the villages of Charivne and Chkalove in the Kherson region, while officers and medical personnel were also evacuated from the town of Beryslav.

On Sunday, Russian officials issued a flurry of statements signaling that their army was digging in and enforcing defensive lines in territory where it has been losing ground or feared encroachment by Kyiv’s forces into areas that Russia now holds. These include the Ukrainian regions of Kherson and Luhansk that Russia illegally absorbed earlier this month, and the Russian regions of Kursk and Belgorod that lie near the Ukrainian border.

“The front line is already starting to prepare for winter,” Kirill Stremousov, the deputy head of the Russian-installed regional administration in Kherson wrote on his Telegram messaging channel. “The front has stabilized. Strengthening the line of contact with people, weapons and equipment continues.”

In a rare pessimistic take on the war effort, the commander of the Russian Armed Forces in Ukraine acknowledged last week that Moscow’s position in the southern Kherson region was tenuous. He said “difficult decisions” might have to be taken, without elaborating.

The recently appointed Gen. Sergei Surovikin said Ukraine had damaged the main bridge used to supply Russian forces in Kherson and a crossing over a dam to the northeast. The priority now is to preserve civilians and military personnel, he said.

Having given civilians the option to leave this week, Russian-installed authorities in Kherson told residents on Saturday to leave the city immediately “because of the tense situation on the front line.”

Moscow sent thousands of soldiers, including some of its best units, to reinforce its defenses in the Kherson region. Ukraine has hampered the Kremlin’s ability to keep those troops supplied by using U.S.-provided long-range rockets to blow up bridges, ammunition dumps and logistics centers.

If Russia’s military is forced to abandon the city—the only Ukrainian provincial capital captured since its February invasion of the country—it would be a significant blow to the Kremlin. Russian President Vladimir Putin feted Kherson as new Russian territory in a ceremony in Moscow less than a month ago following a staged vote on the region’s illegal annexation.

A major Ukrainian advance on the southern front would also demonstrate the ability of Kyiv’s forces to take even well-entrenched Russian positions.

The Washington-based Institute for the Study of War said Russian forces were likely preparing to destroy the dam at the Kakhovka Hydroelectric Power Plant in order to flood and widen the Dnipro River to delay any Ukrainian advances.

Mr. Zelensky accused Russia of mining the dam last week.

Also Sunday, Ukraine’s security service said it had detained the president of aircraft engine manufacturer Motor Sich on charges of collaboration. The president of the company and another employee are accused of colluding with representatives of the Russian military industrial firm Rostec to illegally supply military hardware for Russian attack aircraft.

—Ann M. Simmons contributed to this article.

Write to Isabel Coles at isabel.coles@wsj.com