Major Russian oil refinery knocked offline by Ukrainian drone strike

Russia's second-largest oil refinery, Kirishi, halted processing on Tuesday after Ukrainian drone attacks damaged three of its four crude distillation units (CDU), two industry sources told Reuters.

In an escalation of long-range drone attacks, Ukraine has pummelled Russia's oil industry for the past two months, from pipelines and ports to refineries and tankers, in an effort to undermine Russia's $3 trillion war economy.

Both Russia and Ukraine use swarms of long-range drones to try to smash vital infrastructure far behind the front lines - areas which are now being monitored around the clock by shorter-range drones.