An explosion at the Ilsky Oil Refinery in Russia's Krasnodar Oblast was allegedly caused by a drone attack, Russian state media RIA Novosti reported on May 5.
The news comes after a similar incident was reported by Russian state media TASS on May 4, marking the second consecutive day of such incidents at the refinery.
There have been an increasing number of reports about attacks on railway networks and oil refineries within Russian territory in recent weeks.
According to the U.K. Defense Ministry's report on May 5, these sabotage acts have "almost certainly caused short-term localized disruption" to the Russian military.
A train carrying fuel supplies was derailed in Bryansk Oblast on May 1, while a drone allegedly targeted an oil refinery in Rostov Oblast overnight on May 4.
So far, nobody has stepped forward to claim responsibility for these attacks.