Ukraine on Thursday carried out a drone attack on a Russian oil refinery, just 746 miles from the border, according to a Ukrainian defense source who spoke with Agence France-Presse.

The source said the strike on the Gazprom Neftekhim Salavat oil refinery in the Russian republic of Bashkortostan was "the SBU's work" and was carried out at a "record range."

The attack comes a day after Russian forces unleashed a nighttime barrage of more than 50 cruise missiles and explosive drones at Ukraine's power grid Wednesday, targeting a wide area in what President Volodymyr Zelenskyy called a "massive" attack on the day the country celebrates the defeat of Nazism in World War II.

In recent months, Russian refineries and oil terminals have become priority targets of Ukrainian drone attacks, part of stepped-up assaults on Russian territory.

Ukrainian drone developers have been extending the weapons' range for months, as Kyiv attempts to compensate for its battlefield disadvantage in weapons and troops. The unmanned aerial vehicles are also an affordable option while Ukraine waits for more U.S. military aid.

Information from Agence France-Presse and The Associated Press was used in this report.

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