US President Donald Trump has warned Iran that it will face “dire” consequences if Yemen’s Houthis continue to attack international shipping lanes.

He said the Iranian leadership would from now on be viewed as having pulled the trigger for “every shot fired by the Houthis”, which have long been backed by Tehran.

Trump’s threat came after the Houthis targeted a US aircraft carrier in the Red Sea following US strikes on Yemen that its health ministry said had killed at least 53 people.

The Pentagon said it had launched fresh attacks on 30 targets in Yemen during the attacks that began on Saturday, the biggest US military operation in the Middle East since Trump returned to the White House.

Trump posted on his Truth Social platform on Monday: “Every shot fired by the Houthis will be looked upon from this point forward, as being a shot fired from the weapons and leadership of IRAN.

“And IRAN will be held responsible, and suffer the consequences, and those consequences will be dire!”

The US president accused Tehran of supplying the group with funding, weapons and intelligence, which Tehran denies.

In a letter on Monday to the UN Security Council, Iran’s UN envoy denied it was in violation of a UN arms embargo on Yemen, and said it was not involved in any destabilising activities in the region.

Ambassador Amir Saeid Iravani accused the US of “baseless accusations” against Iran, Reuters news agency reported.

On Monday, Pentagon officials said the escalating US attacks on Yemen were directed at a broader range of targets than the strikes authorised under former President Joe Biden.

Lt Gen Alex Grynkewich said that Houthi drone makers were among those targeted.

He added that there had been “no credible indications of any civilian casualties”.

Washington has said some key Houthi figures were among the dead, but the group has not confirmed this.

“This is not an endless offensive,” said Pentagon spokesman Sean Parnell, adding that the US was not seeking regime change, and would continue to use overwhelming force until its goals are met.

“This campaign will be relentless to degrade their capability and to open up shipping lanes in the region and to defend our homeland,” he added.

On Sunday morning, the Houthis launched drones and missiles targeting the USS Harry S Truman aircraft carrier in the Red Sea.

US fighter aircraft shot down about 11 of the drones, a US official told the BBC’s US partner CBS.

The Houthis also launched a ballistic missile that crashed into the water well short of the USS Harry S Truman, the official added.

The Houthis said at least five children were among 53 people killed in the US air strikes on Yemen’s Al Jaouf and Hudaydah areas, casualties that the BBC has not independently verified.

The US also launched airstrikes against the group on Saturday and Sunday.

The Houthis said they would continue to target Red Sea shipping until Israel lifted its blockade of Gaza.

The Houthis have have claimed – often falsely – that they only target ships linked to Israel, the US or the UK.

Since November 2023, the Houthis have targeted dozens of merchant vessels with missiles, drones and small boat attacks in the Red Sea and the Gulf of Aden.

They have sunk two vessels, seized a third, and killed four crew members.

The rebel group controls Sanaa and the north-west of Yemen, but it is not the country’s internationally recognised government.