Yemen's Iran-backed Houthi rebels took full control of the Bab el-Mandeb Friday when they captured a Red Sea island located in the middle of the vital shipping lane, a local government official and eyewitnesses said.
"Boats carrying armed Houthi fighters reached Mayyun Island after government forces withdrew from it yesterday," the official said, referring to an island also known as Perim that divides the strait into lanes.
"The Houthis have completed their takeover of the Bab el-Mandeb area and Mayyun Island, which is located in the middle of the strait," he added, speaking to Agence France-Presse (AFP) on condition of anonymity.
An eyewitness said gunmen were "deploying along the Bab el-Mandeb shore and are driving around in military vehicles."
Hundreds of people have died since the Iran-backed Houthis launched an offensive around Bab al-Mandab, a vital artery for Saudi oil exports.
'New reality’ in Red Sea
Earlier Thursday, Yemen’s U.N. envoy Abdullah al-Saadi warned the Houthi group's continued military escalation was attempting to impose a "new reality” in the Red Sea.
Speaking during an emergency U.N. Security Council session on Houthi attacks against Saudi Arabia Thursday, al-Saadi said the group’s actions threaten shipping in the strategic waterway.
"The Houthi militia continues its escalation and is attempting to impose a new reality in the Red Sea,” he said.
"The Houthi militia threatens navigation in the Red Sea,” al-Saadi added, warning of the dangers posed by the group gaining control of the Bab el-Mandeb Strait.
"We are defending Bab el-Mandeb as a matter of international and regional security,” he said.
The Yemeni envoy called on the Security Council to condemn the Houthis’ military escalation and enforce its arms embargo against the group.
He said the internationally recognized government had "chosen peace over war and exercised restraint throughout these years," stressing that it would continue "fulfilling its duty to protect its people and institutions."
His remarks came amid escalating clashes between government forces and the Houthis along Yemen’s western coast, which overlooks the Red Sea and lies near the Bab el-Mandeb Strait.
The Houthis have advanced along the western coast in recent days, while local media reported that the group had seized strategic Zuqar Island in the Red Sea near Bab al-Mandeb. Neither the Houthis nor government forces have officially confirmed the report.
Yemeni Presidential Leadership Council Chairman Rashad al-Alimi previously warned about the repercussions of military movements near Bab el-Mandeb.
Foreign Minister Afrah al-Zouba has also urged the Security Council to adopt a "clear and firm position” on the Houthi escalation and the risks it poses to Yemen, the region and the Red Sea.
Fighting between government forces and the Houthis has intensified on several fronts since early July following years of relative calm.
Yemen has been engulfed in conflict since the Houthis seized the capital Sanaa and several provinces in September 2014.
A Saudi-led Arab coalition intervened in March 2015 in support of the internationally recognized government.