Ukrainian soldiers reclaimed control of multiple gas and oil offshore drilling sites in Crimea from Russia on Monday, according to Ukraine’s military intelligence (GUR).

On the Telegram messaging app, it was announced that Kyiv’s soldiers had retaken the drilling platforms known as the “Boiko Towers” in a “one-of-a-kind operation.”

It claimed that Russia had controlled the platforms since 2015, after seizing and annexed Crimea in 2014, and that they had been utilized for military purposes since the start of Russia’s full-scale invasion of Ukraine in February 2022.

Russia did not respond quickly to the news.

“For Ukraine, regaining control of the Boiko Towers was of strategic importance and, as a result, Russia lost the ability to use them for military purposes,” GUR said in a video posted on Telegram.

“Russia has been deprived of the ability to fully control the waters of the Black Sea, and this makes Ukraine many steps closer to regaining Crimea,” it said.

During the operation, GUR said, there was a clash between Ukrainian special forces on boats and a Russian fighter jet, which was damaged and forced to retreat.

GUR also captured other “valuable trophies” such as helicopter munitions and a radar system that can track the movement of ships in the Black Sea, it said.

Before Russia seized the Crimea peninsula, Ukraine extracted a significant part of its natural gas from the Black Sea shelf, providing gas not only for Crimea but also to mainland regions of Ukraine.