Attacks on four ships off the UAE has led Britain's insurers to widen the list of waters deemed as high risk.
At a meeting on Friday, the London insurance market's Joint War Committee extended its list to include Oman, the United Arab Emirates and the Gulf.
It follows attacks on four oil tankers off the coast of Fujairah comprising of Saudi, UAE and Norwegian-flagged ships.
The London insurance market's Joint War Committee issued a statement saying the additions detail areas of perceived enhanced risk for marine insurers and reflect the enhanced regional risk.
"The situation will be kept under close review," the Joint War Committee said.
Its guidance is watched closely and influences underwriters' considerations over insurance premiums.
This week the UAE, Saudi Arabia, and Norway formally notified the UN Security Council regarding the sabotage.
In a joint statement, Abdallah Al Mouallimi, the Saudi permanent representative, said: “It is an act of sabotage that affects the safety of international navigation and the security of world oil supplies.
"While the attacks did not result in any casualties, or spillage of oil or harmful chemicals, they could have caused serious loss of life and an environmental catastrophe in the Gulf of Oman.
So far no one has claimed responsibility for the attacks.
The three countries said they also intended to formally notify the International Maritime Organisation of the attacks and the threat they pose to international shipping.
The decision by the Joint War Committee, which includes Lloyd's Market Association (LMA) members and representatives from other insurance providers, could see insurance premiums increase.
The Joint War Committee normally meets every quarter to review areas it considers high risk for merchant vessels and prone to war, strikes, terrorism and related perils.
It is the first time it has updated the list of high risk areas since last June.
