ADEN, Yemen, Sept. 11 (Xinhua) -- Yemen's Houthi group seized Yemen's entire western coast and pushed its offensive beyond the strategic Bab al-Mandab Strait into the southern province of Lahj on Friday, firing ballistic missiles at retreating government forces, government and military officials said.

Earlier Friday, Houthi forces raided Mayun Island, also known as Perim Island, which lies at the heart of the Bab al-Mandab Strait and divides the narrow waterway into two shipping channels, after government troops withdrew overnight, a government official told Xinhua.

"Houthi naval forces aboard several boats reached Mayun early Friday. They landed on the island and took control without military resistance," the official said, noting that the Houthis now hold "full grip over the Bab al-Mandab area."

The advance followed the Houthis' Thursday capture of Mocha, a strategic Red Sea port city in southwestern Yemen.

"After tightening their grip on Bab al-Mandab and key coastal areas and islands in and around the strait, the Houthis are pressing farther south," a Yemeni military official said Friday on condition of anonymity.

Government forces have pulled back to Khor Omeira in Lahj, about 90 km west of Aden, the temporary seat of Yemen's internationally recognized government in the southern coast, the official said, adding that the forces "are regrouping with no clear indication of their next move."

Residents in Khor Omeira reported signs of disarray among the retreating government forces, with some soldiers said to be selling their weapons at low prices and others discarding their uniforms before heading toward Aden.

As the front line shifted closer to Aden, security forces reinforced the city's western approaches, according to a local security official.

In a statement broadcast by Houthi-run al-Masirah TV on Friday, the Houthi spokesperson Yahya Sarea said the group's offensive, launched on Sept. 3, had seized about 5,400 square km of territory in western Yemen.

He also claimed Houthi forces confronted Saudi warplanes in 32 engagements and "shot down nine aircraft."

The claims could not be independently verified.

Addressing concerns over the security of the Bab al-Mandab Strait, Sarea said international maritime traffic remained "safe," while reiterating that Saudi vessels remained subject to Houthi restrictions.

The Houthis announced a ban on Saudi shipping on July 20 and have since claimed a series of attacks on Saudi tankers and oil facilities in Saudi Arabia.

Bab al-Mandab, which connects the Red Sea with the Gulf of Aden and the Indian Ocean, is a major route for international trade and energy shipments.

Yemen has been embroiled in conflict since late 2014, when the Houthis seized the capital Sanaa and much of the country's north.

The rapid Houthi advance marked the sharpest escalation since a UN-brokered truce in 2022 largely halted major hostilities.