A Russian drone attack has killed four people in the Ukrainian city of Kharkiv and severed power for 350,000 residents while a Ukrainian attack on Russian-controlled parts of the country has killed six civilians, local officials on either side say.
By Thursday evening, power supply limitations had been introduced in six Ukrainian regions due to the latest attacks on grid infrastructure and higher electricity consumption, grid operator Ukrenergo said.
Kharkiv, Ukraine's second-largest city, lies 30km from the Russian border and been one of the worst afflicted as Russia has renewed its missile and drone attacks on the energy system.
Governor Oleh Synehubov said three rescue workers had been killed in a repeat strike after they reached a residential block hit in one attack.
Writing on the Telegram messaging app, he said 12 people were injured, with three in serious condition.
One of the killed rescuers was a 52-year-old firefighter whose son, also a firefighter, had been putting out a fire several buildings away, Interior Minister Ihor Klymenko said.
Realising his father had been killed, the son, Volodymyr, knelt on the ground and wept as two emergency workers consoled him, video shared by Klymenko showed.
President Volodymyr Zelenskiy called the attack "despicable and cynical" in a statement on X, repeating his call to Ukraine's allies to supply more air defences.
Russian-installed officials said a total of six civilians were killed on Thursday in Ukrainian attacks on Russian-controlled parts of southern and eastern Ukraine.
A Russian official in Kherson region, Andrey Alekseenko, said two people died in a village where one drone struck a car and a second drone was fired at a passenger who had managed to crawl away from the vehicle.
He said a separate attack killed two members of a repair crew that was working to restore mobile communications.
Another person was in hospital in critical condition.
Russian-installed officials in Donetsk in eastern Ukraine said two people had been killed there on Thursday by Ukrainian shelling and nine others were wounded.
Russia and Ukraine deny targeting civilians in the war that is now in its third year.
The United Nations Human Rights Monitoring Mission said in February that more than 10,000 civilians had been killed in Ukraine and nearly 20,000 wounded.
Inside Russia, a fire broke out near the central market in the southern city of Kursk on Thursday after air defence units downed a drone, one of four intercepted over the region, governor Roman Starovoit said.
Starovoit, writing on Telegram, said emergency services had been dispatched to the scene.
He said one drone had struck a private home and two fires had broken out in connection with that.
He reported no casualties.
Ukraine's military has repeatedly fired drones at three Russian border regions - Belgorod, Kursk and Voronezh.
Its forces have also shelled border areas, particularly in Belgorod region.
