Oil prices have risen sharply after the killing of a top Iranian general in Iraq.
Analysts warned the action could escalate tensions in the region and affect global oil production.
The price of Brent crude jumped by more than 4% to hit $69.50 a barrel at one point, the highest since mid-September.
It came after General Qasem Soleimani was killed in a US drone strike at Baghdad airport, which the Pentagon described as “defensive action”.
The price spike pushed oil stocks on the London stock exchange higher, with BP up 1.5% and Royal Dutch Shell 1.4% higher.
Tensions between the US and Iran had been rising since the US pulled out of a nuclear deal between Iran and other countries.
This aimed to curb Iran’s nuclear programme and prevent it from developing nuclear weapons. The US has also reimposed sanctions on Iran.
This recent strike has sparked fears of increased risk to energy supplies in the region.
Several of the world’s biggest oil producers can be found in the area, which could be affected if there were a wider military confrontation involving Iran.
As much as a fifth of global supplies pass through the Strait of Hormuz, a narrow passage which provides access to the Gulf.