Thirteen people were wounded, two seriously, when a drone struck an apartment building in the southern Russian city of Rostov-on-Don, the acting regional governor said, according to Reuters.
Three civilians were wounded in the city of Belgorod near the border with Ukraine, according to the governor of that region, who posted video appearing to show a drone striking a car in the centre of the city.
Separately, the head of Russia's Volgograd region said fallen debris from Ukrainian drones had caused a fire at an oil refinery.
There was no immediate comment from Ukraine.
US President Donald Trump and Russian President Vladimir Putin are due to meet in Alaska on Friday as Trump attempts to bring about an end to the 3-1/2-year war.
MNA
Your Comment