A Ukrainian drone attack on Russia's Samara region has left one person dead and three others injured, including a child, according to regional authorities.

The Governor of the Samara region, Vyacheslav Fedorishchev, announced on Sunday that the overnight assault caused casualties and damaged both residential properties and an industrial facility. However, he did not immediately provide additional information about the affected industrial site.

Reports from independent Russian media outlet Astra, citing videos and photographs shared on social media, suggested that the facility targeted during the attack was the Syzran oil refinery.

Images circulating online appeared to show multiple fires burning within the refinery complex following the strike.

Russia's Ministry of Defence also confirmed that its air defence systems intercepted 349 Ukrainian drones overnight, describing the latest assault as one of the largest in recent days.

The Syzran refinery has previously been targeted during Ukraine's long-range drone campaign against Russian energy infrastructure.

Following an earlier attack in late May, the refinery, which has an annual processing capacity of approximately 8.5 million tonnes, reportedly suspended operations for a period.

Owned by the state-controlled energy company Rosneft, the facility is responsible for producing refined petroleum products, including petrol, diesel and aviation fuel.

Repeated strikes on Russian oil refineries have contributed to fuel supply challenges in parts of the country, disrupting production and distribution.

Reports indicate that some petrol stations have introduced fuel rationing measures, while motorists in several locations have experienced long queues due to supply shortages.

Ukraine has intensified attacks on Russia's energy infrastructure in recent months as part of its broader strategy to increase pressure on Moscow and influence the course of the war.

The conflict began after Russian President Vladimir Putin ordered a full-scale invasion of Ukraine more than four years ago.

Despite periodic discussions about a possible negotiated settlement, the two sides remain far apart on key issues. Russia has continued to insist that any future peace agreement must include the transfer of Ukrainian territory, including areas that Russian forces have yet to fully capture.