Gas prices in Europe rose to their highest level in the past four months as the escalating conflict in the Middle East intensifies fears of possible supply shortages next winter.

On Monday, quotations at the Dutch TTF hub (Europe’s benchmark gas index) briefly exceeded €60 per megawatt-hour (MWh), approaching the peak levels seen at the start of the conflict between the US and Iran. This came after the US expanded the scope of its air operation and Iran retaliated with strikes on Bahrain and Kuwait.

Analysts at Independent Commodity Intelligence Services (ICIS) warn that European gas supplies will come under pressure this winter, as the conflict is delaying the expected recovery of liquefied natural gas (LNG) exports from Qatar during the critically important summer storage refill season.

“An early onset of cold weather this winter would significantly increase the cost of reaching the EU’s 80% gas storage target,” said Andreas Schroeder, head of energy analytics at ICIS. “While supply reliability remains assured, the price of achieving it is rising sharply.”

ICIS added that keeping gas prices around €60/MWh may require “potentially costly government intervention to safeguard security of supply,” although according to its modeling, European underground gas storage facilities could still meet their targets by the end of November.

At present, European underground gas storage sites are less than 54% full, compared with 64% at the same time last year.

According to ICIS calculations, since the conflict began on February 28, only 26 LNG tankers have been able to pass eastward from the Persian Gulf, compared with a normal rate of 90 to 100 tankers per month.

In the autumn, European countries may have to pay around €54/MWh to replenish stocks, and in the event of a harsh start to winter, that figure could jump to €60/MWh.

Disruptions to Qatari LNG exports have already affected the global market: ICIS experts cut their forecast for global LNG supply this year from 441 million to 431 million tonnes.

The latest round of escalation, unfolding despite diplomats’ statements that negotiations are still ongoing, is once again threatening shipping through the Strait of Hormuz, through which about 20% of the world’s oil and gas passed before the start of the Iranian conflict.

The fresh exchange of strikes also affected oil markets. On Sunday, Brent crude briefly rose above $90 a barrel, reaching a monthly high, but then eased slightly after Iran said diplomatic contacts with the US through intermediaries were continuing despite the shelling.

Later on Monday, gas prices retreated to about €57/MWh.

“The rise in gas prices to nearly the peak levels seen at the start of the war between the US and Iran is a reminder that any actions taken within the UK have no significant impact on the final gas price we pay,” said Jess Ralston, head of energy at the Energy and Climate Intelligence Unit. “The reality is that we are tightly bound to international markets and to price volatility that has already reached us twice in recent years because of wars thousands of miles away.”