The official, speaking on condition of anonymity, said the US-Iran memorandum of understanding was “entirely performance-based,” warning that Tehran would see benefits only if it showed “good behaviour”.

But US negotiators were continuing to work “in good faith towards a final deal”, the official said.

British maritime security agency UKMTO said an “unknown projectile” hit a tanker overnight, causing a fire, before two more vessels were struck, at least one by a drone.

All three vessels were struck close to Oman, which had proposed a temporary transit corridor hugging its coastline – an initiative opposed by Iran as it seeks to impose fees on ships using the narrow waterway.

Qatar said one of the vessels was its LNG tanker Al-Rekayyat and blamed Iran, denouncing an “unacceptable” attack on international maritime navigation.

Doha later summoned Iran’s deputy ambassador to lodge a complaint, demanding an explanation and urging Tehran to “immediately cease any practices undermining regional security”.

“We hold Iran fully legally responsible for this attack and for any resulting damages or repercussions,” Qatar’s foreign ministry spokesman Majed Al Ansari wrote on X.

Iran voiced “dismay” over Qatar’s accusations in a statement carried by state news agency IRNA, calling the claims “unacceptable”.

Hormuz dispute

The attacks, which ended more than a week of relative calm, revived concerns over freedom of navigation after Iran lifted its blockade of the vital waterway following a fragile ceasefire with the United States.

Oil prices rose by more than 2% as the renewed attacks reignited worries over global energy supplies and cast doubt on the durability of the US-Iran agreement.

“We are now in a sensitive period where potential alternatives to an Iranian toll or fee system are being explored,” Andreas Krieg, a security expert at King’s College London, told AFP.

“Iran is sending a clear signal that no alternative will be accepted.”

Krieg said tankers trying to diverge through the Omani maritime corridor without registering with Iran would be punished, and called the attacks a “clear violation” of the ceasefire agreement and international law.

Maritime traffic had tentatively resumed after Washington and Tehran signed the memorandum last month, but Iran has insisted there will be no return to pre-war arrangements, under which vessels could pass freely through the strait.

Under the 14-point US-Iran memorandum, Iran and Oman, which border Hormuz, must hold talks “to define the future administration and maritime services” in the waterway with other Gulf states.

Qatar had previously refused to mediate under Iranian fire as Tehran launched an unprecedented aerial bombardment against Gulf states in retaliation for the US-Israeli strikes.

But Doha has since taken a more active role, hosting indirect talks between Iran and the United States last week.

– AFP