KYIV, Ukraine (AP) — Ukrainian officials said Russia launched a “massive missile attack” across Ukraine on Monday, striking homes and buildings, disrupting power supplies and causing civilian casualties.

The latest barrage, which Ukrainian authorities have been anticipating for days, was a new round of punishment by Moscow as it sought to disable Ukraine’s energy supplies and infrastructure as winter approaches — part of a new strategy in its nine-month war.

The country’s electricity provider, Ukrenergo, lashed out at Russia over “the eighth massive missile attack by a terrorist country,” saying its facilities had been hit, triggering blackouts. It urged residents to stay in shelters as its crews tried to repair the damage.

In the capital of Kyiv, scores of people quickly congregated in the central Zoloti Vorota metro station after the warnings, and many checked their phones for updates. There were no immediate signs whether the city or the surrounding region was hit.

Air raid alerts sounded across the country. Ukrainian media reported explosions in several parts of the country south of Kyiv, including Cherkasy, Kryvyi Rih and the Black Sea port of Odesa, where the water company said power was out to pumping stations, leaving the city without water.

“The enemy is again attacking the territory of Ukraine with missiles!” Kyrylo Tymoshenko, the deputy head of the Ukrainian president’s office, wrote on Telegram.

Tymoshenko said two people were killed and three others injured — including a 22-month-old child — in the village of Novosofiyivka in the southern Zaporizhzhia region.

Ukrainian air force spokesman Yuriy Ihnat said land-based missiles were launched from southern Russia and shipborne missiles from the Caspian and Black seas. Russian strategic bombers also launched missiles, he said.

Ihnat warned the Russians could attack in several waves to make it more difficult for the Ukrainian air defenses to shoot down the missiles.

Earlier Monday, Russian media reported two explosions at air bases in Russia. One reportedly happened at a base that houses nuclear-capable strategic bombers that have been involved in launching strikes against Ukraine.

Neither Ukrainian nor Russian authorities immediately commented on the possible cause of the blasts.

Russian state RIA Novosti news agency said three servicemen were killed and six others injured and a plane damaged when a fuel truck exploded at an air base in Ryazan, in western Russia. The base houses long-range flight tankers that serve to refuel bombers in the air.

Separately, authorities in the Saratov region along the Volga River said they were checking reports about an explosion in the area of the Engels air base, which houses Tu-95 and Tu-160 strategic bombers that have been involved in launching strikes on Ukraine. Those bombers are capable of carrying nuclear weapons.

Saratov regional Gov. Roman Busargin said there was no damage to civilian facilities and added that the authorities are checking whether there have been any incidents at military facilities.

Regional media reported sounds of a powerful explosion near the Engels base, and some residents were quoted as saying they saw a flash of light coming from the area.

Asked whether Russian President Vladimir Putin had been briefed about the Engels base explosion, Kremlin spokesman Dmitry Peskov said simply that the president was being regularly informed about ongoing developments.

Ukrainian President Volodymyr Zelenskyy’s adviser, Mykhailo Podolyak, trolled the Russians over the drone attack on Engels, stopping short of claiming responsibility:

“The Earth is round – discovery made by Galileo. Astronomy was not studied in Kremlin, giving preference to court astrologers. If it was, they would know: if something is launched into other countries’ airspace, sooner or later unknown flying objects will return to departure point,” Podolyak tweeted.

Zelenskyy’s office said three rocket strikes hit the president’s hometown of Kryvyi Rih in south-central Ukraine, killing a factory worker and injuring three others. In the northeastern region of Kharkiv, a person was killed in strikes by S-300 missiles on civilian infrastructure in the town of Kupyansk, it said.

The war that began with Russia’s invasion of Ukraine on Feb. 24 has displaced millions from their homes, killed and injured an untold number of civilians and shaken the world economy — notably through the fallout on the prices and availability of foodstuffs, fertilizer and fuel that are key exports from Ukraine and Russia.

Western countries Monday imposed a $60-per-barrel price cap and a ban on some types of Russian oil, part of new measures aimed at stepping up pressure on Moscow over the war.

The move has prompted a rejection from the Kremlin and also criticism from Zelenskyy — whose government wants the cap to be half as high.

Russian Deputy Prime Minister Alexander Novak, who is in charge of energy issues, warned in televised comments on Sunday that Russia won’t sell its oil to countries that try to apply the price cap.

“We will only sell oil and oil products to the countries that will work with us on market terms, even if we have to reduce output to some extent,” Novak said in televised remarks hours before the price cap came into effect.

The 27-country European bloc also imposed an embargo on Russian oil shipped by sea.

Russia, the world’s No. 2 oil producer, relies on oil and gas to underpin its economy, which has already come under sweeping international sanctions over the war.

In recent weeks, Russia has been pounding Ukrainian infrastructure — including power plants — with military strikes and keeping an offensive going in the east, notably in and around the town of Bakhmut.

Russian forces have also been digging in near the southern city of Kherson, which was recaptured by Ukrainian forces last month after an 8-month occupation.

In other developments, Russian President Vladimir Putin has driven a vehicle across a bridge to Crimea that was damaged by a truck bomb attack in October.

Putin on Monday took the wheel to drive across the bridge that links Russia’s mainland with the Crimean Peninsula, which Moscow annexed from Ukraine in 2014. He also spoke to workers and discussed the repairs of the Kerch Bridge with a senior government official responsible for the project.

The Oct. 8 truck bomb attack disrupted travel on one of the two automobile lanes of the bridge. Russia blamed the attack on Ukrainian military intelligence and responded with several waves of strikes on Ukraine’s energy facilities and other key infrastructure.