Houthi rebels seize additional islands in the Red Sea

Yemen's Iranian-backed Houthi rebels have captured more strategic islands in the southern Red Sea, government and Houthi officials say, strengthening their control of a major maritime shipping route.

The capture of the islands of Greater and Lesser Hanish came as Saudi-backed government forces attempted to rally over the weekend, attempting to fight back after the rebels' lightning advances around the Bab el-Mandeb, a crucial shipping alternative to the Strait of Hormuz.

The Houthi rebels deployed fighters on the Hanish islands, 160 kilometres north of Bab el-Mandeb, after hundreds of government-allied forces withdrew from the archipelago, according to two government officials and a Houthi official.

The officials spoke on condition of anonymity on Monday because they are not authorised to talk to journalists.

The Houthis' new gains further enable the group to threaten Saudi crude oil shipments, which have used the Red Sea as a substitute to the Strait of Hormuz, where Iran has been attacking shipping.

The escalation, especially Houthi attacks on Saudi oil infrastructure and its shipping endeavours across the Red Sea, adds to mounting pressure on global oil supplies and prices, which could give Iran leverage in its war with the United States.

The new capture of the Greater and Lesser Hanish islands comes after the rebels last week seized the port city of Mokha on Yemen's mainland, and the island of Mayun, located inside the Bab el-Mandeb Strait.

The Houthis' advances also put them just 32 kilometres from the US military base in Djibouti, on the other side of the Bab el-Mandeb Strait.

The Saudi Civil Defense sent an all clear early on Monday after issuing alerts for potential danger in the southern cities of Najran, Khamis Mushait, Jazan and Abha. It also later issued warnings for Khamis Mushait and Abha a second time before lifting them again.

On Sunday, Houthi officials released a statement claiming they had attacked the Saudi Khamis Mushait air base.

The advances came with little resistance from forces of the internationally recognised government. But over the weekend, those forces sought to regroup, and the Yemeni military advanced toward the strategic town of Dhubab, north of the strait.

The fighting is pushing Yemen back into full-fledged civil war, after a truce that largely proved to be successful during the past three years.