Foreign minister Jeremy Hunt said on Sunday Britain is "almost certain" Iran was behind attacks on oil tankers in the Gulf of Oman, adding that London did not believe anyone else could have done it.
On Saturday, Iran summoned the British ambassador to Tehran after London blamed it for the attacks, the semi-official Students News Agency ISNA reported.
Asked whether Iran was behind the attacks on the tankers, Hunt told the BBC's Andrew Marr show: "We have done our own intelligence assessment and the phrase we used is almost certain ... We don't believe anyone else could have done this."
"We are urging all sides to de-escalate."
The Royal Navy plans to deploy 100 marines to the Persian Gulf to protect British ships after a series of attacks on vessels, the Telegraph newspaper reports.
Plans for the deployment began several weeks ago and a security committee is expected to meet this week to discuss the matter, the paper reported without revealing the source of the information.
Four oil vessels were targeted off the coast of the United Arab Emirates last month. The U.S. deployed naval and air force assets to the region in response to the elevated risk.
© 2021 Thomson/Reuters. All rights reserved.