Iran on Monday vowed to respond to any "adventurism", its foreign ministry said, after the US and Britain joined Israel in blaming Tehran for a deadly tanker attack, claims it denies.
The MT Mercer Street, managed by prominent Israeli billionaire Eyal Ofer, was attacked on Thursday off Oman.
A British security guard and a Romanian crew member were killed in what the United States, Britain and the vessel's operator Zodiac Maritime said appeared to be a drone strike.
Israel blamed Iran for the attack, accusations rejected by Tehran.
Iran's foreign ministry spokesman Saeed Khatibzadeh said Sunday that Israel "must stop such baseless accusations".
The US and Britain on Sunday also then blamed Iran for the attack, with Washington vowing an "appropriate response".
Iran "will not hesitate to protect its security and national interests, and will immediately and decisively respond to any possible adventurism," ministry spokesman Khatibzadeh said in a statement.
He dismissed US and Britain's statements as "contradictory", and said "if they have any evidence to support their baseless claims they should provide them".
Khatibzadeh also accused them of effectively supporting "terrorist attacks against and sabotage of Iran's commercial ships" through their "silence".
There have been several recent reported attacks on Iranian ships that Tehran has linked to Israel.
In March, Iran said it was "considering all options" after an attack on a cargo ship in the Mediterranean, that it blamed on Israel.
In April, Tehran said its freighter Saviz was hit by an "explosion" in the Red Sea, after media reports said Israel had targeted the ship.
The New York Times reported at the time that this was an Israeli "retaliatory" attack, after "Iran's earlier strikes on Israeli ships".
Iran has also accused Israel of sabotaging its nuclear sites and killing a number of its scientists.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)