Iran accused the United States of breaching their ceasefire Tuesday after overnight US strikes targeting Iranian missile sites and mine-laying boats threatened diplomatic efforts to strike a deal to end the war.
The Brent benchmark oil price jumped up by almost three percent after US Central Command announced the new wave of bombings, and China urged both sides to respect the truce and to resolve their dispute peacefully.
According to the maritime safety monitor UKMTO, a blast damaged a tanker on the waterline off Oman -- although the crew and vessel were reportedly safe after what was described as an "external explosion".
Iranian state media reported overnight blasts in the southern port city of Bandar Abbas, near the Strait of Hormuz, and the country's Revolutionary Guards Corps said its forces had downed a US drone entering its airspace and had fired at an F-35 fighter jet.
"The US terrorist army, continuing its illegal and unjustified actions since the ceasefire ... has, in the past 48 hours, committed a gross violation of the ceasefire in the Hormozgan region," the Iranian foreign ministry said, AFP reported.
It added that Tehran "will not leave any evil unanswered and will not hesitate to defend the Iranian nation," without elaborating.
In a statement marking the start of the Eid al-Adha holiday, Tehran's supreme leader Mojtaba Khamenei declared that Washington was losing its influence in the Middle East and warned countries in the region to stop hosting bases from which the US could launch attacks.
The United States, he said in a written statement, "in addition to no longer having any safe haven in the region for aggression and the establishment of military bases, is moving further and further away from its former position with each passing day".
Tim Hawkins, a spokesman for US Central Command, said: "US forces conducted self-defence strikes in southern Iran today to protect our troops from threats posed by Iranian forces."
- 'We'll see' -
He gave few details of the attacks and said only that the targets included missile launch sites and boats trying to "emplace mines."
Despite the strikes, Secretary of State Marco Rubio said on Tuesday that a deal remained within reach.
But he remained firm on the Strait of Hormuz, the key oil and gas shipping route out which Iran is seeking to control.
"There were some talks going on in Qatar today, so we'll see if we can make progress. I think it's a lot of talking back and forth going on about specific language in the initial document, so it'll take a few days," Rubio told reporters, during a visit to India.
He said the strait was "going to be open one way or the other," adding: "What's happening there is unlawful, it's illegal, it's unsustainable for the world, it's unacceptable."
Tasnim news agency said Tehran's negotiators are seeking the release of frozen assets, with half to be made available once an inital memorandum of understanding is signed.
This came as a top Iranian delegation was in Qatar and Tehran said it was finalizing a 14-point framework for a deal on ending the war, which began with US-Israeli airstrikes on February 28.
"Iran's frozen assets are to be released during the course of the negotiations, and this amount is estimated at $24 billion in accordance with the 14-point memorandum of understanding," Tasnim said.
- Frozen assets -
Iran's top negotiator, parliamentary speaker Mohammad Bagher Ghalibaf, arrived in Qatar on Monday for talks along with Foreign Minister Abbas Araghchi and Central Bank Governor Abdolnaser Hemmati.
Tasnim said Ghalibaf's trip was "aimed at reaching an understanding on the implementation of Iran's demand and the method of accessing $12 billion in the first phase".
In 2023, $6 billion in frozen Iranian funds held in South Korean banks was transferred to Qatar pending the release of five American citizens detained in Iran.
The new strikes threaten the ceasefire that began on April 8 as the US and Iran struggle to reach an accord.
China, Washington's great power rival and a major energy importer, expressed concern.
"We urge the parties concerned to fulfil their ceasefire commitments, resolve disputes through peaceful means... and promote the early restoration of peace," foreign ministry spokeswoman Mao Ning told reporters.
Hopes of an accord took another blow when Israeli Prime Minister Benjamin Netanyahu vowed to "crush" Hezbollah in Lebanon on Monday.
Iran has demanded that any peace accord apply to the fighting in Lebanon as well.
On Tuesday, Israel warned Lebanese civilians to evacuate the southern city of Nabatieh ahead of more planned strikes.
