Last month, Trump ordered large-scale strikes on areas controlled by the Houthis and threatened that they would be “completely annihilated”.
He has also warned Iran not to arm the group – something it has repeatedly denied doing.
On Sunday, the US military said weapons storage and manufacturing facilities had been among targets it had struck, but said it would not “reveal specifics” about ongoing operations.
The US said it “would continue to ratchet up the pressure” until Houthi attacks on vessels are halted.
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 Houthis have said they are acting in support of the Palestinians in the war between Israel and Hamas in Gaza, and have claimed – often falsely – that they are targeting ships only linked to Israel, the US or the UK.
The Houthis were not deterred by the deployment of Western warships in the Red Sea and Gulf of Aden to protect merchant vessels last year, or by multiple rounds of US strikes on military targets ordered by former President Joe Biden.
After taking office in January, Trump redesignated the Houthis as a “Foreign Terrorist Organisation” – a status the Biden administration had removed due to what it said was the need to mitigate the country’s humanitarian crisis.
Over the last decade, Yemen has been devastated by a civil war, which escalated when the Houthis seized control of the country’s north-west from the internationally-recognised government, and a Saudi-led coalition supported by the US intervened in an effort to restore its rule.
The fighting has reportedly left more than 150,000 people dead and triggered a humanitarian disaster, with 4.8 million people displaced and 19.5 million – half of the population – in need of some form of aid.
