Yemen's national airline said on Tuesday a commercial flight had landed at Aden international airport after acquiring security permits, a step that will ease a blockade on one of the poorest Arab nations.

The Saudi-led military coalition fighting Yemen's Houthi movement said last week it had closed all air, land and sea ports in Yemen to stem what it said was the flow of arms to the Houthis from Iran. The move came after Saudi Arabia intercepted a missile fired towards Riyadh, which it blamed on Tehran.

Iran denies arming the Houthis and blames the conflict in Yemen on Riyadh. The United Nations has warned a total blockade could cause famine in Yemen, where war has killed at least 10,000 people in the last two and a half years.

Transport Minister Mourad al-Halimi had said Yemenia flights to the pro-Saudi-government-held cities of Aden and Seiyun would resume on Sunday, but the national carrier said it did not have the necessary permits to fly.

On the other hand, At least 11 fighters from the Shia Houthi militia and its allies were killed in clashes with government forces in Yemen’s southwestern Taiz province, a military source said Thursday.

“Fierce fighting erupted when Houthi rebels staged an attack in the Shaqab region east of the Sabr al-Modam directorate, which is the southern entrance of Taiz city,” Walid al-Ashbat, a Yemeni army commander, told Anadolu Agency. According to al-Ashbat, 11 Houthi fighters were killed in the clashes, including the commander of the militia’s sniper division. Three government military personnel, he added, had been injured in Wednesday’s melee.

Anadolu Agency was unable to obtain immediate comment from Houthi spokesmen regarding the army commander’s assertions.

Al-Ashbat went on to assert that the Houthis and their allies had retreated from the area after being repulsed by government forces, which, he said, were now advancing on Taiz city’s Houthi-held southern entrance.

Most parts of the city are currently under the control of government forces and pro-government volunteer fighters known as “popular resistance” committees. Impoverished Yemen has remained in a state of civil war since 2014, when Houthi rebels overran much of the country, including capital Sanaa.

The conflict escalated in 2015 when Saudi Arabia and its Arab allies launched a massive air campaign aimed at rolling back Houthi gains and shoring up Yemen’s pro-Saudi government.