US President Donald Trump has launched military strikes against Yemen's Iran-aligned Houthi rebels over the group's attacks against Red Sea shipping, warning "hell will rain down upon you" if the Houthis do not abandon their campaign.
Mr Trump also warned Iran, the Houthis' main backer, that it needed to immediately halt support for the group, adding that if Iran threatened the United States "America will hold you fully accountable and, we won't be nice about it!"
The unfolding US strikes, which a US official told the Reuters news agency would continue for days, if not weeks, represent the biggest US military operation in the Middle East since Mr Trump took office in January.
They coincide with the US ramping up sanctions pressure on Tehran while trying to bring it to the negotiating table over its nuclear program.
At least 13 civilians were killed and nine injured in US strikes on Yemen's capital Sanaa, according to the Houthi-run health ministry.
Six others, including four children and one woman, were killed and 11 were injured in a US strike on the northern province of Saada, the Houthi-run Al-Masirah TV reported.
The Houthis' political bureau described the attacks as a "war crime".
"Our Yemeni armed forces are fully prepared to respond to escalation with escalation," it said in a statement.
Residents in Sanaa said the strikes hit a building inside a Houthi stronghold.
"The explosions were violent and shook the neighbourhood like an earthquake. They terrified our women and children," said Abdullah Yahia, who lives nearby.
The Houthis have launched more than 100 missile and drone attacks targeting international shipping in the Red Sea since November 2023, saying they were in solidarity with Palestinians over Israel's war with Hamas in Gaza.
Iran's other allies, Hamas in Gaza and Hezbollah in Lebanon, have been severely weakened since the start of the conflict, while Syria's Bashar al-Assad, who was closely aligned with Tehran, was overthrown by rebels in December.
But during this period, Yemen's Houthis have remained resilient and on the offensive, sinking two vessels, seizing another and killing at least four seafarers in an offensive that has disrupted global shipping, forcing firms to re-route to longer and more expensive journeys around southern Africa.
The attacks initially targeted ships connected with or travelling to or from Israel, but ships with ties to Israeli allies the US or the United Kingdom have come under attack more recently.
The previous US administration of president Joe Biden had launched strikes against Houthi targets in Yemen, but had limited US actions to degrading the group's ability to attack vessels off the country's coast.
US officials, speaking on condition of anonymity, say Mr Trump has now authorised a more aggressive approach, which appeared to match his rhetoric on Saturday.
"The Houthi attack on American vessels will not be tolerated. We will use overwhelming lethal force until we have achieved our objective," Mr Trump wrote.
The attack marks the first strikes to hit Yemen since the Gaza ceasefire deal took effect in January.
On Tuesday, the Houthis said they would resume attacks on Israeli ships passing through the Red and Arabian seas, the Bab al-Mandab Strait and the Gulf of Aden, ending a period of relative calm starting in January with the Gaza ceasefire.
US ramps up nuclear pressure on Iran
The US attacks came just days after a letter from Mr Trump was delivered to Iran's Supreme Leader Ayatollah Ali Khamenei, seeking talks over Iran's nuclear program.
Mr Khamenei on Wednesday rejected the notion of holding negotiations with the United States.
Still, Tehran is increasingly concerned that mounting public anger over economic hardships could erupt into mass protests, four Iranian officials told Reuters.
Last year, Israeli strikes on Iranian facilities, including missile factories and air defences, in retaliation for Iranian missile and drone attacks, reduced Tehran's conventional military capabilities, according to US officials.
Iran has denied wanting to develop a nuclear weapon. However, it is dramatically accelerating its enrichment of uranium to up to 60 per cent purity, which the UN's nuclear watchdog has warned will make it easier to reach the roughly 90 per cent enrichment needed for weapons-grade material.
Western states say there is no need to enrich uranium to such a high level under any civilian program, and that no other country has done so without producing nuclear bombs.
Iran denies wanting to develop a nuclear weapon, saying its nuclear program is peaceful.
Reuters/ABC
