In a town without basements, residents of Ukraine's "Venice" on the Danube have no way to hide underground from the increasingly frequent Russian drone attacks on the country's river and deep sea ports.

Russia and Ukraine traded drone attacks overnight, with Russian officials saying on Saturday that Ukrainian strikes had killed one person in the Belgorod border region. Russia said it had downed 47 Ukrainian drones overnight, while Ukraine reported it neutralised 24 drones fired by Moscow.

Up to 400 Iran-made drones may have been destroyed in the fiery blast, while a military airbase in Southern Russia was also attacked.