Cruise missiles were used in Saturday's attacks on Saudi oil facilities, and the attack came from Iran, a US official cited by AFP has claimed.
The official, who declined to be named, told the news agency that the US was now gathering evidence about the attack to present at the UN General Assembly next week.
Asked if the US was certain that the cruise missiles was launched from Iranian soil, the official curtly answered "Yes."
Asked how many missiles were fired, the official declined to answer. "I will not get into that kind of details," the official said.
Earlier, anonymous officials told the Wall Street Journal that US intelligence agencies had handed their Saudi counterparts a secret report implicating Iran in the attacks. According to the officials, the attacks involved some 20 drones and at least a dozen missiles.
The US began claiming that Iran was responsible for the oil facility attacks just hours after they occurred, with Secretary of State Mike Pompeo calling on the international community to "publicly and unequivocally condemn Iran's attacks" on "the world's energy supply." President Trump later joined Pompeo in accusing Iran, warning that the US was "locked and loaded" to respond, but "waiting to hear from the Kingdom" on the culprit and "under what terms we would proceed!"
Iran's foreign ministry said the US's allegations were "unacceptable and entirely baseless." Iranian Foreign Minister Mohammad Javad Zarif charged Washington with switching from a strategy of "maximum pressure" to one of "maximum deceit" with its latest claims. The US, he said, won't succeed in ending the disastrous war in Yemen by "blaming Iran" for everything.
Yemen's Houthi militia, who claimed responsibility for the attack on Sunday and repeated their claims on Monday, have accused Riyadh of "cowardice" with its attempt to "exonerate Yemen from conducting these strikes" while "accus[ing] others of doing them." The militia said they carried out the attacks on the facilities using 10 kamikaze drones.
On Monday evening, a spokesman from the Saudi-led military coalition said preliminary findings had led Riyadh to conclude that Saturday's attacks used Iranian-made weapons, and were not launched from Yemen.
Tensions between Iran and the US and its allies began to ramp up earlier this year, after the US deployed a carrier strike group to the Middle East in early May in response to what Washington said was an 'imminent threat' to its interests in the region. About two weeks after the US deployment, multiple tankers suffered suspected sabotage attacks off the coast of the United Arab Emirates. The US blamed Iran. A month later, while Japanese Prime Minister Shinzo Abe was on a goodwill visit to Tehran, two more tankers were sabotaged, including one belonging to Japan. The US blamed Iran. Tehran denied claims of its involvement in both instances, calling the attacks "suspicious" and accusing the US and its regional allies, including Israel, Saudi Arabia and the UAE of deliberately exacerbating tensions.
Iran has repeatedly criticised the US and its allies for building up their military presence in the Persian Gulf, and warned Sunday that all US bases and warships in Iran's vicinity were "within range of its missiles" in the event of US aggression.
Yemen's Houthi movement has launched dozens of missile and drone attacks against military and infrastructure targets in Saudi Arabia in recent years, attacking everything from airports and military bases to US missile defence systems and cities using small drones and ballistic missiles. US officials have repeatedly accused Iran of supplying the militants with their weapons. Tehran has denied the claims, however, pointing to the Saudi-led coalition's blockade against Yemen's ports, which it said has led to a humanitarian crisis in much of the country. A coalition of mostly Gulf countries plus Egypt began a military intervention in Yemen in March 2015, seeking to defeat the Houthis and restore ousted Yemeni President Abdrabbuh Mansur Hadi to power.