Russian attacks on nine Ukrainian regions triggered emergency power outages affecting hundreds of thousands of households, damaged homes and injured at least 15 people, officials said Friday, as civilian casualties continue to rise.
The strikes came amid growing concerns that deteriorating relations between Kyiv and Washington could leave Ukraine more vulnerable to Russian attacks ahead of winter.
Russia has repeatedly targeted Ukraine's energy infrastructure before winter, seeking to weaken public support by disrupting heating and water supplies. Ukrainian officials have warned that Moscow is stockpiling ballistic missiles for further attacks.
Ukraine abandoned a brief truce on energy targets on Thursday, accusing Russia of violating the arrangement despite US President Donald Trump's call for a ceasefire.
Ukrainian President Volodymyr Zelenskyy attended a European Union summit in Brussels on Friday, where leaders pledged continued support and urged Washington to increase pressure on Russian President Vladimir Putin.
Tensions escalated after Trump and Zelenskyy exchanged sharp remarks this week. Zelenskyy said he felt betrayed by Trump, who openly expressed his dislike for the Ukrainian leader.
Zelenskyy also criticised disruptions in Western intelligence sharing and restrictions on Starshield, SpaceX's military-grade satellite internet service used in Ukraine's drone operations and military communications.
Ukraine faces a shortage of US-made Patriot missiles needed to counter Russian ballistic missile attacks. Zelenskyy also criticised Trump's diesel deal with Russia, while Ukrainian officials accused the US president of pressuring Kyiv to surrender territory.
EU foreign policy chief Kaja Kallas said European leaders were trying to persuade Washington to maintain its support for Ukraine.
Meanwhile, a UN human rights report said 328 civilians were killed and 2,105 injured in Ukraine in September, an 85% increase from the same month last year. UN official Danielle Bell said the first two weeks of October were among the deadliest periods for civilians in years.
Russia's Defence Ministry said its air defences intercepted 644 Ukrainian drones overnight. Nearly 160 flights were delayed or cancelled at Moscow's four airports, while another 46 were disrupted at St Petersburg airport, local media reported.