Russia launched a new wave of missile attacks on cities across Ukraine on Tuesday, days after the country celebrated retaking the key southern city of Kherson, one of the most dramatic setbacks yet for President Vladimir Putin’s war.

The apparently coordinated barrage on key cities from Lviv in the west to Kharkiv in the northeast hit residential buildings in the capital, Kyiv, and struck energy infrastructure, knocking out power to areas across the country.

It came as world leaders, including President Joe Biden, met at a summit of the Group of 20 nations in Indonesia that has been dominated by Russia’s invasion.

Kyiv Mayor Vitali Klitschko said on his Telegram channel that two residential buildings were hit in the city’s Pechersk district, while several missiles were intercepted and shot down. There was no immediate report of casualties, but Klitschko said rescuers and medics were on the scene.

Air raid sirens were heard across the city and the wider Kyiv region, and people were urged to stay in shelters.

Lviv Mayor Andriy Sadovyi said that parts of the city were without power after explosions were heard.

Officials in the western city of Rivne and the country’s second-largest city, Kharkiv, reported damage to major infrastructure and loss of electricity.

NBC News has not verified the reports.

Ukrainian Foreign Minister Dmytro Kuleba said in a tweet that the strikes should put an end to pressure for peace talks with Russia.

While the retaking of Kherson was welcomed in Ukraine, the country’s leaders cautioned that the war is far from over and that Putin could retaliate for the humiliation of his forces’ retreat in the south.

Russia continues to fire some 20,000 artillery rounds a day, according to U.S. security officials.

Russia has yet to comment on the strikes and has consistently denied targeting civilians.

Facing a series of battlefield setbacks, it has increasingly attacked civilian infrastructure including energy facilities ahead of winter.