The Iran-backed Houthis (Ansarallah) on Sunday (February 28) claimed missile and drone strikes that targeted Saudi Arabia from positions in Yemen overnight and threatened more attacks, as fighting in the grinding civil war escalates.
Houthi fighters have intensified operations against the kingdom as Arab coalition airstrikes pound their positions in the north of Yemen, in a bid to stop their offensive to seize the government's last northern stronghold of Marib.
Saudi Arabia said Saturday it thwarted a Houthi missile that targeted Riyadh.
According to Houthi spokesman Yahya al-Saree, via the Houthis' Al-Masirah TV channel, "a ballistic missile and 15 drones" targeted "sensitive areas" in Riyadh.
Fragments of the missile scattered over several Riyadh neighbourhoods, damaging at least one home, Saudi state-run Al-Ekhbariya television said.
No casualties were reported.
Separately, the Arab coalition said it had intercepted six Houthi drones targeting the kingdom, including the southern cities of Khamis Mushayt and Jizan.
Al-Saree on Sunday claimed those attacks as well, warning residents in the region to "stay clear from all military airports and sites".
Arab League secretary general Ahmed Aboul Gheit condemned the Houthis' escalation, as did Organisation of Islamic Co-operation (OIC) secretary general Yousef bin Ahmed al-Othaimeen.
Gulf Co-operation Council (GCC) secretary general Nayef Falah Al-Hajraf also condemned the attacks.
Jordan, Qatar, Bahrain, Kuwait, Egypt, Somalia and the UK were among the countries who reached out to Saudi Arabia to condemn the Houthis' violence.
The United States said Sunday it "strongly condemns" the Houthi attacks on population centres in Saudi Arabia.
"These attacks threaten not only innocent civilians but also prospects for peace and stability in Yemen," said State Department spokesman Ned Price.
"We call on the Houthis to end these egregious attacks and engage constructively with UN special envoy Martin Griffiths and US special envoy Tim Lenderking with the goal of bringing peace, prosperity and security to the Yemeni people," he said.
"The United States remains committed to its longstanding partnership with the Kingdom of Saudi Arabia and to helping Saudi Arabia defend its territory as it faces attacks from Iranian-aligned groups," he added.
US President Joe Biden recently halted support to Saudi offensive operations in Yemen's war, which he called a "catastrophe" that "has to end".
But he also has reiterated US support for Saudi Arabia in defending its territory.
On Sunday, in the latest violence in Yemen, five civilians, including a child, were killed when their home was destroyed in a bombardment near the strategic Red Sea port of al-Hodeidah, which is controlled by the Houthis.
The warring sides traded blame over who was responsible.
Houthi offensive in Marib
Alongside the cross-border attacks, the Houthis are pressing ahead with an offensive to seize government-held Marib province, where some of the country's richest oil fields are found.
Hundreds of fighters from both sides have been killed in recent ferocious fighting, government sources say.
The Houthis control most of the country's north and the government has been struggling to defend Marib province and the city.
Yemen's conflict has claimed tens of thousands of lives and displaced millions, according to international organisations, sparking what the UN calls the world's worst humanitarian crisis.
The UN on Monday hopes to raise $3.85 billion at a donor conference to support millions of civilians and prevent famine in the country.
"I implore all donors to fund our appeal generously to stop famine engulfing the country," UN chief António Guterres said at the start of the virtual conference, in which more than 100 governments and donors are taking part.
UN Development Programme country director Auke Lootsma on Sunday urged the international community to "rally around Yemen and come forward with a great number of pledges that will help us to prevent a widespread famine".
He warned as well that with the infrastructure damage caused by the conflict, Yemen is now witnessing "the worst development crisis in the world" and risks becoming an "unviable state".