Four people were killed in a wave of Russian strikes across Ukraine on Wednesday, the government said, as US envoy Steve Witkoff headed to Saint Petersburg for talks. Ukraine's Prime Minister Sergiy Koretsky said two people were killed when a drone hit a 24-storey building in the capital, Kyiv, while two others were killed in the northeastern Kharkiv region. The head of the Kharkiv regional state administration, Oleg Synegubov, said the victims were an elderly couple, aged 81 and 83. Emergency services found their bodies under the rubble after their house was destroyed. The latest attacks came as Witkoff on Tuesday wrapped up talks with Ukraine's President Volodymyr Zelensky in Norway before heading to Russia on Wednesday to meet President Vladimir Putin. US Secretary of State Marco Rubio described the talks as "positive", after rising tensions between Kyiv and Washington in recent weeks over the course of the nearly five-year war. Koretsky wrote on Telegram that Russian forces had struck energy infrastructure, railways, shopping centers and residential buildings "continuously" since Tuesday night. Further strikes included one on a university building in the central city of Kremenchuk, and attacks on energy facilities in Kyiv, Volyn in the northwest, and Odesa and Mykolaiv in the south. Koretsky also said a drone attacked a merchant vessel in the Black Sea. Power company DTEK said emergency power outages were imposed on three parts of Kyiv alongside planned power cuts elsewhere in the city.