Ukraine’s capital came under one of the biggest attacks of the war on Friday as Russia’s invading forces fired dozens of missiles across the country, triggering widespread emergency power outages, Ukrainian officials said.

Gunfire from air defense systems and thudding explosions combined with the wail of air-raid sirens as the barrage targeted critical infrastructure in cities including Kyiv, Kharkiv, Kryvyi Rih and Zaporhizhzhia. The head of the Ukrainian armed forces said they intercepted 60 of 76 missiles launched.

Russian strikes on electricity and water systems have occurred intermittently since mid-October, increasing the suffering of the population as winter approaches. But the Ukrainian military has reported increasing success in shooting down incoming rockets and explosive drones.

Friday’s attack took place after the United States this week agreed to give a Patriot missile battery to Ukraine to boost the country’s defense. Russia’s Foreign Ministry warned Thursday that the sophisticated system and any crews accompanying it would be a legitimate target for the Russian military.

The U.S. also pledged last month to send $53 million in energy-related equipment to help Ukraine withstand the attacks on its infrastructure. John Kirby, spokesman for the White House National Security Council, said Friday that the first tranche of that equipment and technical support had arrived in the country.

More than half of the Russian missiles fired Friday targeted Ukraine’s capital. The city administration said Kyiv withstood “one of the biggest rocket attacks” it has faced since Russia invaded Ukraine nearly 10 months ago. Ukrainian air-defense forces shot down 37 of about 40 missiles that entered the city’s airspace, and one person was injured, it said.

Ukraine’s air force said Russian forces had fired cruise missiles from the Admiral Makarov frigate in the Black Sea, while Kh-22 cruise missiles were fired from long-range Tu-22M3 bombers over the Sea of Azov, and tactical aircraft-fired guided missiles.

In Kryvyi Rih in central Ukraine, President Volodymyr Zelenskyy’s hometown, a missile slammed into a four-story residential building and left a gaping hole in its upper floors. Three people were killed and at least 13 were taken to the hospital, said Igor Karelin, deputy head of the city’s emergency services.

Rescue teams with sniffer dogs searched through the debris for a missing mother and her 18-month-old child.

Also at Kryvyi Rih, nearly 600 miners were stuck underground because of the missile strikes and were being rescued, Mayor Oleksandr Vilkul said on state TV. Vilkul said about 250 of them had been rescued and the operation was continuing.

He said “several energy infrastructure facilities were completely destroyed.”

State-owned grid operator Ukrenergo wrote on Facebook that priority in restoring power across Ukraine was being given to critical infrastructure, including hospitals, water supply facilities, heat supply facilities and sewage treatment plants.

Friday’s attack was “the ninth wave of missile strikes on energy facilities,” Ukrenergo said, and because of the repeated damage, “the restoration of power supply may take longer than before.”

Analysts have said Russian strikes targeting energy infrastructure are part of a strategy to try to freeze Ukrainians into submission after recent battlefield losses by Russian forces. Officials and experts say that has only strengthened the resolve of Ukrainians to face up to Russia’s invasion, while Moscow tries to buy time for a possible offensive in coming months after the current battlefield stalemate.

The southeastern city of Zaporizhzhia and its surrounding region were hit by 21 rockets early Friday, city council secretary Anatoly Kurtev said. Lights went out in some areas, but there were no initial reports of injuries.

Kharkiv regional governor Oleh Syniehubov reported three strikes on critical infrastructure in that city, Ukraine’s second-largest, while Kyiv Mayor Vitali Klitschko reported explosions in at least four districts.

“The attack on the capital continues,” Klitschko wrote on social media. Subway services in Kyiv were suspended, he said, as residents sought shelter in its tunnels.

At the site of one attempted strike in Kyiv, military commanders told The Associated Press that the city’s territorial defense mobile group had shot down a cruise missile with a machine gun. It wasn’t immediately clear whether other Ukrainian fire may have contributed to downing the rocket.

“Almost impossible to hit a missile with a machine gun, but it was done,” said a commander who goes only by the call sign “Hera” for security reasons.

Ukrzaliznytsia, the national railway operator, said power was out in a number of stations in the eastern and central Kharkiv, Kirovohrad, Donetsk and Dnipropetrovsk regions. But trains continued to run after electric power was switched to backup, steam-engine power.

In neighboring Moldova, the state-owned energy company reported disruptions to its electricity network as a result of Russia’s strikes on Ukraine, and warned of a “high risk” of power outages.

Moldova — whose Soviet-era systems remain interconnected with Ukraine’s — has already suffered two massive blackouts in recent months as Russia attacked Ukraine’s energy grid.

The previous such round of massive Russian air strikes across Ukraine took place on Dec. 5.

“Grateful for the work of Ukraine’s air defense amid more escalatory Russian attacks this morning on civilian infrastructure in Kyiv and around the country,” the U.S. ambassador in Kyiv, Bridget Brink, wrote on Twitter.