KIEV, June 28 (Xinhua) -- Ukrainian President Volodymyr Zelensky said Sunday that Ukrainian forces had carried out overnight strikes on two oil refineries in Russia.

In a post on X, Zelensky said one of the targets was the Slavyansk oil refinery in Russia's Krasnodar region, about 300 km from the frontline.

Local media reported that the refinery has an annual processing capacity of some 4 million tons of oil.

He said another refinery in Russia's Yaroslavl region, about 700 km from the Ukrainian-Russian border, was also targeted, but did not give further details.

Zelensky said the strikes were aimed at weakening Russia's ability to sustain its war effort.

"Each of our long-range sanctions means fewer resources serving Russia's war machine, and another step toward peace," he wrote. ■