The Department for Transport has issued new guidance to all British-flagged ships to go to a heightened state of security in the Strait of Hormuz, Sky News reports.
The guidance was issued in recent days in response to concern about an increased threat from Iran in the Gulf, two maritime industry sources said.
British-flagged ships have been advised to keep alert for Iranian patrol boats “being aggressive towards them”, one of the sources said.
A separate shipping industry source said his vessels are increasing the number of watch keepers on deck, trying to move through the Strait of Hormuz during daylight hours and travelling at a faster pace than usual to keep safe.
A Department for Transport spokeswoman said: “The Department for Transport, as competent authority, regularly provides Security Advice to UK and Red Ensign Group Shipping on how they should operate in areas of high risk.”
It comes after three Iranian boats tried to stop a British oil tanker – HMS Montrose – in the Strait, a situation the UK government said it was “concerned by”.
The British warhip gave a warning and deployed its helicopter, a wildcat, which circled the Iranians, before their boats withdrew.
However, Iran’s Revolutionary Guard denied claims of a confrontation, saying: “There were no clashes with alien boats, especially English boats.”