KYIV, Ukraine >> Ukraine’s capital came under one of the biggest attacks of the war today as Russia’s invading forces fired dozens of missiles across the country, Ukrainian officials said, reporting strikes in at least four cities that triggered widespread emergency power outages.

Gunfire from air defense systems and thudding explosions combined with the wail of air raid sirens as the barrage targeted critical infrastructure in Kyiv, Kharkiv, Kryvyi Rih and Zaporhizhzhia. The head of the country’s armed forces said Ukrainian forces intercepted 60 of the 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.

Today’s attack took place after the United States this week agreed to give a Patriot missile battery to Ukraine to further 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.

More than half of the Russian missiles fired today targeted Ukraine’s capital. The city administration said Kyiv had 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” 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.

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 by the call sign “Hera.”

Another commander, a military post chief named “Yevhen,” said the machine gunner who intercepted the missile “reacted quickly” and fired, and green sparks flew from the rocket as it began to spin and tumble to the ground.

Neither commander would give their real full names, citing security reasons

Electricity and water services were interrupted in parts of the country, including in the capital and Ukraine’s second-largest city, Kharkiv. Thousands of people sought shelter in subway stations deep underground during the bombardment.

State-owned grid operator Ukrenergo wrote on Facebook that emergency shutdowns were triggered across the country. Priority in restoring power will be given to critical infrastructure facilities, including hospitals, water supply facilities, heat supply facilities, and sewage treatment plants, it said.

Today’s’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 were part of a new 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.

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, with rubble spilling onto the ground. Two people were killed and at least 13 others were taken to the hospital, said Igor Karelin, deputy head of the city’s emergency services.

Rescue teams with sniffer dogs combed through the debris to search for a missing mother and her 18-month-old child. Karelin said the search was precarious because of the risk that rubble still dangling on the building could fall.

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

Kharkiv Mayor Ihor Terekhov said on Telegram that the city was without electricity. Kharkiv regional governor Oleh Syniehubov reported three strikes on the city’s critical infrastructure. Kyiv Mayor Vitali Klitschko reported explosions in at least four districts and urged residents to go to shelters.

“The attack on the capital continues,” he wrote on the social media app. Subway services in the capital were suspended, he said, as city residents flocked inside its tunnels to seek shelter.

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, due to damage to the energy infrastructure. But trains continued to run by switching from electric power to steam-engine power, which had been readied as a backup.

In neighboring Moldova, the state-owned energy company Moldelectrica 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 the country took place on Dec. 5. Ukrainian authorities have reported some successes in intercepting and downing incoming missiles, rockets and armed drones in recent weeks, including today.

“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.