Iran-aligned Houthi forces have reached and taken control of Perim Island, also known as Mayun, in the Bab el-Mandeb Strait, in a major territorial advance that could put further pressure on one of the world’s most important shipping routes and Saudi Arabia’s alternative oil-export corridor, news agency Reuters reported.Houthis have also reached the Yemeni town of Dhubab , which sits directly on the Bab el-Mandeb Strait across from the island of Perim, two Yemeni government sources told Reuters on Friday.Reuters also cited four Yemeni government sources on Friday confirming that the Houthis had reached the strategically located island after government forces withdrew. Two Saudi-backed Yemeni government sources had earlier said Houthi forces also captured the mainland coastal town of Dhubab, which faces Perim across the Bab el-Mandeb.The Mayun island is a small volcanic outcrop which lies about 3.5 km off Yemen’s western coast.Why the Houthi capture of Perim mattersPerim’s location gives the Houthis a potentially significant position overlooking the Bab el-Mandeb Strait, which connects the Red Sea with the Gulf of Aden. The waterway has become particularly important as the conflict around the Strait of Hormuz has disrupted another major route for global energy shipments. Saudi Arabia has increasingly depended on the Red Sea route to move crude after Iran effectively shut the Strait of Hormuz, through which roughly a fifth of global oil had previously flowed. Thus, gaining greater control over the Bab el-Mandeb could therefore give the Houthis and their Iranian backers additional leverage over a crucial alternative route.Must Read | Pakistan warns Houthi attacks on Saudi Arabia could activate Mecca defence pact: What it meansThe threat extends beyond oil. The Bab el-Mandeb is a major corridor for international trade, and the AP reports that around 12 per cent of the world’s goods typically pass through the waterway.Story continues below this ad Yemen’s Houthi rebels ride a motorbike during a mobilization campaign in Sanaa, Yemen, Thursday. (AP photo)Shipping through the strait had already fallen sharply after the Houthis began attacking vessels in late 2023. Activity subsequently increased as Saudi Arabia sought alternatives to Hormuz, but renewed Houthi threats have curtailed that traffic, according to Lloyd’s List Intelligence cited by Associated Press.The latest territorial gains could therefore increase pressure on shipping companies while adding another potential source of volatility to global oil prices.Saudi Arabia retaliates after Houthi advanceSaudi Arabia has responded militarily to the Houthi offensive.According to the AP, Saudi forces carried out airstrikes against the airport in Mokha, the Red Sea port city captured by the Houthis on Thursday. The Houthi broadcaster reported the strikes, although there was no immediate information on damage or casualties and Saudi Arabia had not immediately commented.Story continues below this adThe Houthis, meanwhile, have warned that they could retaliate further. Houthi political bureau member Hazam al-Assad told AP there was “no need for international concern” and said the group had “a bank of big important targets” if Riyadh continued its attacks.Iran has also backed the Houthis politically. Iran’s Foreign Ministry called for an end to Saudi Arabia’s blockade of Yemen and urged a return to negotiations between Riyadh and the Houthis, according to AP.The escalation comes after the Houthis launched attacks on Saudi Arabia earlier this week. Reuters reported that the group struck energy facilities linked to Saudi oil giant Aramco in Abha, Najran and Jizan on September 8, causing fires and temporarily disrupting operations at some sites. Saudi authorities said 73 people were wounded.Also Read | ‘How’s it going, Trump?’: Iran shares Akshay Kumar meme to mock US PresidentReuters also reported that satellite imagery showed smoke on Thursday near Saudi Arabia’s East-West oil pipeline, another strategically important piece of infrastructure that allows Riyadh to move crude from its eastern oil-producing areas towards the Red Sea. There was, however, no confirmation from Saudi authorities or Aramco that an incident had occurred at the location shown in the imagery.Story continues below this adHouthis move closer to a critical maritime chokepointThe seizure of Perim follows a rapid Houthi expansion along Yemen’s Red Sea coast.According to a Reuters report, Yemeni government forces were preparing a counter-offensive and planned to deploy weapons and aircraft against Houthi positions in strategic areas, including routes leading towards Mocha. Yemeni military spokesman Colonel Majed al-Nazili urged civilians to avoid the road between Taiz and Mocha and stay away from Houthi military equipment.The development marks a significant shift in the geography of the conflict. The Houthis have traditionally concentrated their control in northern Yemen and the country’s most populous areas, but their latest offensive has pushed them south along the Red Sea coastline and towards the Bab el-Mandeb.Reuters also reported that Yemeni, Iranian and regional sources said Iran’s Islamic Revolutionary Guard Corps had provided direct guidance to the Houthis as part of an effort to open another front in Tehran’s conflict with the United States. The report quoted two Iranian sources who said Tehran had instructed the Houthis to intensify attacks on Saudi Arabia and promised additional funding and weapons. Iran publicly denies directing the Houthis and maintains that the group is “not a proxy”.Story continues below this adMocha capture set the stage for the Perim advanceThe takeover of Perim came a day after the Houthis captured Mocha, a historic Red Sea port that lies roughly 80 km from the Bab el-Mandeb Strait.Four Yemeni government military sources told Reuters that the Houthis had seized the port city, while the AP reported that residents said Houthi forces had entered and spread through the city, although it could not independently verify those accounts.The capture of Mocha was the Houthis’ biggest territorial gain against their Saudi-backed Yemeni opponents in years, according to AP. The city overlooks tanker routes leading out of the Red Sea and brought the Houthis significantly closer to the Bab el-Mandeb.