Ali Larijani
Ali LarijaniReuters

Iran's parliament speaker, Ali Larijani, hinted on Sunday that Washington could be behind the "suspicious" tanker attacks in the Gulf of Oman in an attempt to pile pressure on Tehran, AFP reported, citing the Iranian IRNA news agency.

"The suspicious actions against the tankers... seem to complement the economic sanctions against Iran considering that (the US) has not achieved any results from them," Larijani told MPs.

He backed his claim by saying there had been a precedent "during World War II, when Americans targeted their own ships near Japan to create an excuse for hostility."

A Japanese-owned tanker, the Kokuka Courageous, and a Norwegian-operated one, the Front Altair, were attacked on Thursday and left ablaze as they were passing through the Gulf of Oman

US President Donald Trump has said the twin attacks had Iran "written all over it", rejecting Tehran's vehement denial.

US Secretary of State Mike Pompeo similarly accused Iran of being behind the attacks in the Gulf of Oman.

The US Central Command later released footage that purports to show the crew of an Iranian patrol boat removing an object from the hull of the Japanese tanker.

Iran's Foreign Minister Mohammad Javad Zarif dismissed the US claim as "baseless" and said Washington had "immediately jumped to make allegations against Iran -- (without) a shred of factual or circumstantial evidence."

Thursday’s attack came a month after attacks on four tankers off the coast of the United Arab Emirates on May 12. Two of the ships targeted in that attack were Saudi oil tankers that were en route to the United States.

The incidents come amid increased tensions between the US and Iran, a year after Trump withdrew from the 2015 nuclear deal between Iran and world powers and imposed several rounds of crippling sanctions on the Islamic Republic.

Iran announced last month it was suspending some of its commitments under the 2015 deal in response to the US withdrawal in May of last year.

In addition, tensions between the two longtime foes has increased after Washington sent more military forces to the Middle East in a show of force against what US officials say are Iranian threats to its troops and interests in the region.