UK officials expect Russia to retaliate for seizure of shadow fleet oil tanker

No formal warning issued to captains or ship owners, but industry body says they are exercising greater vigilance

British officials believe Russia will try to retaliate for the Royal Marines’ seizure of the oil tanker Smyrtos, prompting UK ship owners to exercise greater vigilance until tensions with Moscow ease.

Military sources said the UK had considered possible responses to the seizure of the vessel carrying Russian crude worth $40m (£30m) to India, and anticipate that the Kremlin will want to hit back.

“Seizing the Smyrtos was in the works for a long period. They had gone through the risks, and expectation is Russia will try to retaliate,” said a naval insider. “If they do so, it could be globally. They are likely to take their time and pick their moment.”

No formal warning has been issued to British captains and ship owners, but the UK Chamber of Shipping, which represents the industry, said there was an understanding that there could be the risk of a Russian tit-for-tat action.

“We are aware of the increased risk and owners assess the risk for themselves,” said a spokesperson. “From an industry perspective, a greater vigilance is more prevalent, given the events of the last few days.”

The Smyrtos was seized in the small hours of Sunday on the orders of the British prime minister, Keir Starmer, as it sailed 25 miles (40km) south of the Isle of Wight. Its Indian captain has been charged with breaching UK sanctions on Russia .

On Tuesday, sailors on a Russian frigate, the Admiral Grigorovich, fired warning shots near a British yacht in the Channel. The pleasure boat, which was on its way to the French port of Cherbourg, had come close to the warship, though the couple on board said they had already taken evasive action when the shots were fired.