At least 13 people were injured in the city of Kursk after debris from a destroyed Ukraine-launched missile fell onto a nine-storey residential building, officials of the Russian border Kursk region said on Sunday.

Moscow's forces are in their sixth day of intense battles against Kyiv's largest incursion into Russian territory since Russia launched a full-scale invasion on its smaller neighbour, with local authorities rushing to evacuate areas at risk.

Alexei Smirnov, Kursk's acting governor, said in a post on the Telegram messaging app that two of the injured were in serious condition.

Residents of the building were to be evacuated to a temporary accommodations centres, Kursk Mayor Igor Kutsak said on Telegram. He added that the whole city was under air raid alerts.

Kutsak posted a photo of a residential building with blown out windows and damaged balconies and facade of a residential building at night.

Reuters could not independently verify the reports from Kursk. There was no immediate comment from Ukraine.

Both Kyiv and Moscow deny targeting civilians in their attacks in the war, which has killed thousands of people and misplaced millions of Ukrainians, and has no end in sight.

  - Reuters