The Houthis have taken control of Yemen’s entire Red Sea coast and pushed onto islands around the strategic Bab al-Mandeb Strait, according to media reports.

The group seized the last coastal towns in a rapid advance against forces of the internationally recognised Yemeni government early on Friday, consolidating its position along the maritime route linking the Red Sea with the Gulf of Aden.

Two Yemeni government sources told an international media outlet that Houthi forces had reached Dhubab, a coastal town that sits directly on the Bab el-Mandeb Strait opposite Perim Island. Government sources had said on Thursday that control of Dhubab and Perim would be key to gaining control of the strait.

The Houthis have also reportedly reached Perim Island, which sits at the mouth of the Red Sea and divides the Bab el-Mandeb Strait. Yemeni government officials said that government forces had withdrawn from the island. The Houthis had not immediately confirmed that they had reached Perim.

The Bab el-Mandeb Strait connects the Red Sea with the Gulf of Aden and serves as a passage for oil, fuel and international trade. The Houthi advance has therefore raised concerns over movement through the waterway, which links Asia and Europe.

The latest developments follow the Houthis’ seizure of the strategic Yemeni port city of Mocha on Thursday. The group then pushed south along the Red Sea coast towards the Hanish islands before reaching Dhubab and moving onto islands in the Bab el-Mandeb Strait.

The developments come as Saudi Arabia’s increased reliance on its Red Sea export route after disruption to traffic through the Strait of Hormuz during the wider conflict with Iran. Millions of barrels have instead been shipped through the Saudi port of Yanbu.

Meanwhile, Houthi military spokesman Yahya Sarea said the group would announce details of a “large-scale, high-impact military operation”.

In a post on Telegram, Sarea said a statement was expected but did not provide further details about when it would be issued.