A tanker was attacked in the Strait of Hormuz Sunday, a British maritime agency said, hours after Tehran warned there was no military solution to the Middle East conflict and the key waterway would remain closed until its conditions were met.
Iran has sought to impose control over the vital shipping lane since the start of its war with the United States and Israel.
It has repeatedly targeted vessels in the waterway that it accuses of transiting without its authorization, while the United States has struck ships allegedly attempting to skirt a counterblockade of Iranian ports.
An "unknown projectile" struck the ship but the crew were unharmed, the United Kingdom Maritime Trade Operations Centre (UKMTO) said.
No environmental impact had been recorded from the attack, it added.
The agency did not specify the date of the incident, the vessel's origin or destination, or whether it was an oil tanker or LNG carrier.
The Strait of Hormuz, through which about one fifth of the world's oil and gas transited before the war, remains a key sticking point in negotiations between Iran and the U.S.
The latest attack came just hours after Iran's parliament speaker Mohammad Bagher Ghalibaf said the Strait will not reopen until seven Iranian conditions set out in a June interim agreement are met, Iran's Nournews reported.
"The Americans, who say something different in the media, have recently put forward proposals through a mediator. But they must understand that the period of dragging out the process and dictating one-sided demands is over," Ghalibaf was quoted as saying.
"The position of the Islamic Republic of Iran is completely clear and firm, and the Strait of Hormuz will not be opened until our seven conditions, based on the Islamabad Memorandum of Understanding, are met."
Iranian Foreign Minister Abbas Araghchi said separately Sunday there was no military solution to his country's conflict with the United States, with talks on ending the war apparently at an impasse.
"If our enemies again choose the path of military confrontation, our response will be stronger than before, and we will defend ourselves with even more force," Araghchi said at a gathering of foreign ambassadors.
"There is no military solution, nor any solution based on new sanctions," he continued, adding "only negotiations based on justice and fairness" could end the conflict.
After a U.S.-Israel campaign of heavy bombardment failed to bring a decisive close to the war, Washington in recent weeks has dialed back military operations in favor of economic pressure.
The two sides agreed a memorandum of understanding in June aimed at providing a framework for a permanent resolution, but the deal collapsed, largely due to disagreements over Hormuz.
Iranian and U.S. officials last week held indirect talks on the sidelines of the U.N. General Assembly, with Tehran saying it presented seven conditions for reopening the strait.
Trump, however, rejected the proposal, while leaving the door open both to further talks or renewed military operations.
Araghchi reiterated that a plan put forward by Tehran to resolve its dispute with Washington could lead to the Strait of Hormuz reopening within seven days if accepted.
