TEHRAN -- A crude oil supertanker was burning in the Strait of Hormuz on Saturday after striking a naval mine while attempting to exit the strategic waterway via an unauthorized route, the Islamic Revolution Guards Corps (IRGC) Navy said, as European gas storage hit its lowest seasonal level since 2011 and crude prices climbed to $104 per barrel.

The IRGC Navy said the tanker had switched off its navigation and positioning systems before the incident, triggering a "powerful explosion" and a massive fire visible to people on the coast.

"A massive fire awaits any violating oil tanker that seeks to disregard the security and regulations of the Strait of Hormuz," the IRGC warned.

The incident follows a surge in maritime attacks in the waterway. At least 13 incidents involving oil, LNG and LPG tankers were recorded around the strait between September 28 and October 5, the highest weekly total since the U.S.-Israeli terrorist war on Iran began on February 28.

Brent crude closed at $104.72 per barrel on Friday, up 0.42%, while WTI settled at $91.85, up 0.39%. Crude has returned to relatively high levels after WTI fell below $89 and Brent around $100 earlier in the week.

The European Union is heading into winter with gas storage about 72.4% full as of October 3, the lowest for this time of year since records began in 2011.

The Institute for Energy Economics and Financial Analysis warned the bloc may need to cut winter gas demand by 7%, or 14 billion cubic meters, compared with last winter.

Combined with the EU's full ban on Russian LNG imports from January 2027, the storage shortfall could require a 14 bcm reduction in demand. Covering the gap with imports would cost approximately €3 billion, a 12% premium over 2025 prices due to the war on Iran.

EU gas storage levels are 15 percentage points below the five-year average for this time of year. Dutch TTF futures traded around €78 per megawatt-hour on Friday, near two-week highs and up 5.6% week-on-week.

European Commission President Ursula von der Leyen told the European Parliament that gas prices have risen 140% since late February and diesel prices have doubled. The EU has paid an extra €100 billion for fossil fuel imports "without a single molecule of additional energy," she said.

EU Energy Commissioner Dan Jørgensen urged member states to lower their storage refill target from 90% to 80% to prevent panic buying.

The EU is also facing severe diesel shortages. West Asian diesel exports have fallen to a quarter of pre-war levels, while Russian exports dropped to about 20% of May levels in August. EU diesel imports fell to about 1 million barrels per day in September, roughly 600,000 bpd below 2025 levels.

Average EU diesel prices reached a record €2.24 per liter, with 12 member states hitting all-time highs. The EU average of $9.63 per gallon compares with $6.52 in the U.S.

The G7 agreed on October 2 to release 100 million barrels of emergency oil and diesel stocks over four months. Analysts at Wood Mackenzie estimated the release could lower wholesale prices by $20 to $30 per barrel, but warned the effect would be temporary without restored West Asian supply flows.

Kirill Dmitriev, Russian President Vladimir Putin's special envoy, said the EU's "self-inflicted" gas shortage stems from its own policies. "Severe, self-inflicted gas shortage in the EU winter," he wrote, responding to reports that the bloc faces a 14 bcm shortfall.