India, June 29 -- Russian President Vladimir Putin made a rare public concession on Sunday, acknowledging that his country is experiencing fuel shortages and queues at petrol stations across its regions, even as Ukrainian drones struck two major oil refineries in a single overnight campaign, setting one ablaze in a fireball visible for kilometres.

Putin acknowledged on Sunday that fuel supply problems had created shortages in Russian regions, and said a task force was working to ensure sufficient quantities were provided throughout the country.

Speaking with characteristic understatement at a conference of his ruling United Russia party, he told the nation it was navigating a "difficult period," without once uttering the word Ukraine or...