Ukrainian forces appear to have broken through a Russian defense line in the southern region of Zaporizhzhia and are trying to advance to a key hub further south. Russia's military has reportedly deployed its elite airborne troops.

Ukraine's military said on Monday that its troops recaptured Robotyne, a settlement in the Zaporizhzhia region. Ukraine apparently aims to let its forces reach the road and rail hub Tokmak further south.

The US think tank Institute for the Study of War said on Monday that Russia's military apparently deployed elements of the 76th Guards Air Assault Division to reinforce positions near Robotyne from the eastern region of Luhansk. The move indicates that fighting is likely to intensify in the area.

Russia's defense ministry said on Monday that its Aerospace Forces detected unmanned aerial vehicles of the US MQ-9 Reaper and RQ-4 Global Hawk flying over the southwestern part of the Black Sea. It said Russian fighter jets were scrambled and the US reconnaissance UAVs changed their flight direction and left the areas.

The ministry on the previous day announced detection of an MQ-9A Reaper's flight over the Black Sea.

Ukraine recently carried out repeated drone attacks on the Russian-annexed southern region of Crimea and reportedly conducted a landing operation there.