The GUR, Ukraine’s military intelligence, stated that Kyiv’s forces had retaken the drilling platforms known as the “Boiko Towers” in a “unique operation”.
It said the platforms had been occupied since 2015 by Russia, which seized and annexed Crimea in 2014, and had been used by Moscow for military purposes since the start of Vladimir Putin’s full-scale invasion in February 2022.
Russia did not immediately comment on the report which could not be independently verified.
⚡️Special forces of the Main Directorate of Intelligence of the Ministry of Defense of 🇺🇦Ukraine at one of the so-called "Boika Towers" pic.twitter.com/EEErPuLlT7
— 🇺🇦Ukrainian Front (@front_ukrainian) September 11, 2023
“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.
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.
Ukraine said on Monday that its troops had regained more territory on the eastern and southern fronts in the past week of its counter-offensive against Russian forces.
Deputy Defence Minister Hanna Maliar said in televised comments that Ukraine had retaken nearly two square km (0.77 square mile) of land around the eastern town of Bakhmut, captured by Russia in May after months of fierce fighting.
She later added on the Telegram messaging app that the Ukrainian army had in the past week also recaptured 4.8 square km (1.8 sq miles) in the southern Tavria sector.
In her televised comments, Ms Maliar said Ukrainian forces had captured part of the village of Opytne, south of the eastern city of Avdiivka, and had "partial success" near the village of Novomaiorske in the eastern region of Donetsk.
She reported "some success" near the villages of Andriivka and Klishchiivka south of Bakhmut.
Ukrainian troops have regained control of about 49 square km (19 sq miles) near Bakhmut since the start of the counter-offensive in early June, Ms Maliar said. In the Tavria direction, over 256 square km (99 sq miles) had been recaptured, she added.
Kyiv has retaken a series of villages and settlements in the counter-offensive, but its soldiers have been hampered by vast Russian minefields and trenches.
Ms Maliar’s claims could not be independently verified. Russia has disputed some recent reports of Ukrainian advances.
Meanwhile, Ukraine's foreign minister said he discussed air defence supplies with his German counterpart in Kyiv on Monday and that Ukraine needed more systems to protect its ports from Russian air strikes to ensure grain could be exported.
Dmytro Kuleba also urged Berlin to send Taurus missiles to Ukraine as soon as possible.
"You will do it anyway, its just a matter of time, and I don't understand why we are wasting time," he said in response to a question at a news conference in Kyiv.