Kharkiv Mayor Ihor Terekhov said on the Telegram messaging app that four people died at the scene of one attack, at least three of them rescue workers, the Reuters news agency reported.
The rescue workers were killed after they arrived at the scene and a new strike occurred, according to Terekhov.
More than 10 other people were injured, officials said.
Kharkiv Regional Governor Oleh Synehubov said that at least four strikes had hit the city, damaging residential buildings, according to Reuters.
He wrote on Telegram that the body of a civilian woman had been discovered, Ukrainian state news agency Ukrinform reported.
"At least 10 people were injured as a result of the occupiers' attack on Kharkiv," Synehubov said in his post. "A 49-year-old man is in serious condition, other patients are in moderate and fair condition."
Ukraine's air defence forces said they had destroyed 11 of 20 attack drones launched by Russia against Ukraine overnight into Thursday.
"In the early hours of April 4, 2024, Russia attacked the Kharkiv region with Shahed-131/136 UAVs from the Kursk region," the Ukrainian Air Force Command said on its Facebook page.
"In total, 20 Shaheds were launched," the post added, as cited by Ukrinform.
Russia invaded Ukraine on February 24, 2022, starting the largest armed conflict in Europe since World War II.
Thursday is day 771 of Russia’s war on Ukraine.
(gs)
Source: IAR, PAP, Reuters, Ukrinform