The Ukrainian military has carried out attacks in the Caspian Sea damaging three Russian oil platforms, the General Staff in Kyiv says on Telegram.
The platforms, belonging to Russian oil company Lukoil, are used to supply Russia's forces in Ukraine, the General Staff said.
The military said it hit V Filanovsky, Yuri Korchagin and Valery Grayfer platforms.
Ukraine gave no details of the type of attack but claimed "direct hits," which makes the use of long-range drones plausible.
"The extent of the damage is being assessed," it said.
The military's information could not be independently verified.
The Russian military generally does not provide information on damage from Ukrainian attacks.
Ukraine has repeatedly targeted oil and gas industry facilities in Russia to complicate supplies for occupying troops.
European Commission head Ursula von der Leyen said on Sunday it was up to Russia to show it is interested in peace after Ukraine and its allies agreed on a peace plan and security guarantees that would take effect following a ceasefire.
Von der Leyen told reporters the peace plan was the 20-point proposal that Ukrainian President Volodymyr Zelenskiy discussed with US President Donald Trump at the end of last year.
She added that, alongside the plan, there were substantial, robust and well-defined security guarantees for Ukraine from the United States and the European Union.
"Now, Russia has to show that they are interested in peace," von der Leyen said.
She said the security guarantees would rely first on Ukraine's armed forces, which she said were well-trained and battle-experienced.
It would be the task of European countries to make sure the Ukrainian army is also well equipped, she said.
The second line of defence would be the so-called "coalition of the willing" - 35 states including most EU countries as well as Canada, the United Kingdom, Australia, New Zealand and Turkey.
"Here it is very good that the Americans are involved, specifically in the verification and the monitoring but also with a backstop," von der Leyen said.
She said that the EU was working on plans to ensure Ukraine's economic prosperity after a ceasefire, with ideas to be spelled out in a forthcoming "prosperity paper".
The document would set out measures for the short-term and over the next decade to boost Ukraine's economy and support its recovery.
with Reuters
