The French navy on Thursday intercepted a crude oil tanker on the high seas in the Alboran Sea which was sailing from Murmansk in the northwest of Russia.

French maritime authorities said the ship is suspected of operating with a false flag. The French Navy is escorting the ship to port for more checks, the statement said.

The French navy, with the assistance of allies including the UK, boarded the vessel on Thursday on the high seas in the Mediterranean.

“We will not tolerate any violation. This morning, the French Navy boarded an oil tanker coming from Russia, subject to international sanctions and suspected of flying a false flag. The operation was conducted on the high seas in the Mediterranean, with the support of several of our allies. It was carried out in strict compliance with the United Nations Convention on the Law of the Sea,” French president Emmanuel Macron said in a post on X about the interception, with a photo showing a French helicopter hovering over a ship.

“A judicial investigation has been opened. The vessel has been diverted. We are determined to uphold international law and to ensure the effective enforcement of sanctions,” Macron wrote in his post.

According to a separate statement from the Maritime Prefecture of the Mediterranean, the vessel was diverted on January 22 and is currently being escorted by French Navy to an anchorage for further investigation.

The operation was supported by allies from other countries, including Britain, the statement added.

Ukrainian president Volodymyr Zelenskyy said in a post on X that the operation was “exactly the kind of resolve needed.”

He suggested the oil carried by these tankers to be confiscated and sold.

“This is exactly the kind of resolve needed to ensure that Russian oil no longer finances Russia’s war. Russian tankers operating near European shores must be stopped. Sanctions against the entire infrastructure of the shadow fleet must be tough. Vessels must be apprehended. And wouldn’t it be fair to confiscate and sell the oil carried by these tankers?” he wrote on X.

The case was referred to the prosecutor of Marseille, who ordered the ship to be diverted for further investigation.