Ukraine has used long-range drones to attack Russian oil platforms as it expands its strikes on the country's energy sector.

Ukrainian drone attack in southwestern Russia killed two people as parts of Ukraine went without power after Russian assaults on energy sites hours before peace talks were to restart in Germany.

Ukraine’s cheap, effective drones boost defense and exports, but extensive politicization and complex bureaucracy risk slowing production at a critical moment.

The drones are still in limited supply and are not always the ideal interception method, Ukrainian soldiers and an official told Business Insider.

The Russian submarine was allegedly carrying Kalibr cruise missiles, which Russia has used in devastating strikes on critical infrastructure and military targets across Ukraine. The SBU said the submarine was “put out of action” as a result of the blast. The FT could not independently verify the claim.

A drone attack in Russia's Saratov region has killed at least two people and damaged a residential building. Local authorities reported the incident on Saturday.

Ukraine's drone schools are preparing soldiers to take on Russia and working to keep pace with an ever-changing fight.