European natural gas prices rose more than 4% on Monday to above €74/MWh, their highest level in more than three and a half years, as escalating US-Iran tensions threatened to disrupt energy supplies from the Persian Gulf. Iran said it had targeted oil tankers and several US-linked vessels and planned to establish a restricted maritime zone beyond the Strait of Hormuz in the coming days. The statement followed US strikes on Iranian oil tankers, which Washington said were retaliation for Tehran’s missile attacks on US Navy warships. The ongoing escalation has increased concern that Qatari LNG (liquefied natural gas shipped by sea) deliveries to Europe could face further delays. European storage facilities were around 62% full as the region approached the end of its summer injection period, below the five-year seasonal average, leaving it more exposed to competition for supplies and winter price spikes.