Russian forces have attacked Kyiv in Ukraine, killing at least eight people and injuring more than 36 people.Drones and missiles struck residential buildings and started a fire in a hotel on a central boulevard.Ukrainian President Volodymyr Zelenskyy had earlier warned of a possible attack on Wednesday night, local time, and said he was cutting short his visit to Dublin for the start of Ireland's six-month term in the rotating presidency of the European Union.Tymur Tkachenko, head of the capital's ​military administration, said eight people had been killed, with about three dozen locations across the city damaged in the attacks. He did not elaborate.Kyiv Mayor Vitali Klitschko, writing on Telegram, said separately that 34 more were injured, adding that among the damage, the first to sixth floors of an apartment building collapsed after a direct hit.Reuters video footage showed emergency services working through the rubble of what used to be a nine-storey building as the sun started to rise over Kyiv.In an earlier post, Mr Klitschko said the injured included paramedics and drivers at an ambulance station, and that some people were still trapped inside damaged residential buildings.Pictures posted online showed a fire burning out of control at the top of a building on the central Shevchenko Boulevard, while elsewhere in the city, windows blew out and cars were destroyed. Multiple explosions were heard in Kyiv, a Reuters witness said.People carried children, belongings, tents and pets, and crowded into underground stations as air raid alerts were issued for most of Ukraine's territory on Thursday in Russia's worst attack on the country since mid-June."Another horrific night for the residents of the city, who were forced to spend it in shelters," Olha Stefanishyna, Ukraine's ambassador to the United States, said in a post on X.Neighbouring Poland, a NATO and European Union member, briefly scrambled fighter jets on Thursday, local time, as a preventive measure before calling them back and saying no airspace violation was recorded.Smoke rises from an apartment building damaged overnight in Kyiv. (Reuters: Valentyn Ogirenko)Ukraine intensifying strikes deeper into RussiaMr Zelenskyy has proposed talks with Russian President Vladimir Putin to end the more than four-year war, which the Kremlin leader has rejected.Ukraine has recently intensified strikes deeper into the Russian territory, triggering a widespread fuel crisis in the world's third-biggest oil producer and forcing it to import gasoline from as far away as India.Governor Alexander Drozdenko of Russia's north-western Leningrad region, Mr Putin's home and where large export and oil refining facilities are located, said on Telegram Russian forces brought down seven drones on Thursday, local time.Neighbouring Finland, a NATO and European Union member like Poland, briefly issued a temporary aviation restriction zone in the eastern Gulf of Finland before lifting it, its defence forces said on X.Russia's strikes on Kyiv left a crater on a residential street. (Reuters: Valentyn Ogirenko)In the Russian Belgorod region bordering Ukraine, a man was killed and his wife injured after a drone hit their home, local authorities said separately on Telegram.Reuters could not independently verify details of the casualties. Russia and Ukraine say they do not deliberately target civilians.Reuters