UK natural gas prices rose further to above 114 pence a therm on Wednesday, the highest in almost a month, as renewed tensions in the Middle East stoked fears of a new wave of supply disruptions.
Reports indicate that Iran launched drones targeting US military sites in Bahrain and Kuwait.
Earlier, Washington carried out airstrikes on Tehran and revoked a license permitting Iran to sell oil after three merchant vessels were struck in the Strait of Hormuz.
The fresh attacks threaten the interim deal reached last month that had reopened the vital shipping route.
Additional support came from forecasts of an intense heatwave across parts of Northwest Europe, which is expected to boost electricity demand for air conditioning and increase gas-fired power generation.
This comes amid a slower-than-usual pace of seasonal storage replenishment.
Moreover, flows from Norway, currently the region's largest single pipeline supplier, fell slightly after seasonal maintenance was extended.