Al-Qaeda captures major airport in southern Yemen

Military officials and residents say al-Qaeda has taken control of a major airport, a sea port and an oil terminal in southern Yemen after brief clashes with troops.

The officials said al-Qaeda fighters clashed Thursday with members of one of Yemen's largest infantry brigades outside Mukalla, a city the militants overran earlier this month.

The officials, speaking from Sanaa, said the leaders of the brigade fled.

The brigade is in charge of securing the coast of Mukalla, the provincial capital of Yemen's largest province, Hadramawt. After seizing the airport, the militants easily captured the sea port and oil terminal.

UN envoy resignation

The UN's special envoy to Yemen, Jamal Ben Omar, "has expressed an interest in moving on to another assignment. A successor shall be named in due course," a UN statement said.

Ben Omar oversaw Yemen's National Dialogue Conference in 2013, and sought to help steer international efforts to keep Yemen's post-2011 transition on track.

Speaking on Wednesday, Ben Omar, a Moroccan who holds British citizenship, rejected the idea that he was at fault for Yemen's current strife.

"Our job as the United Nations was... to act as a mediator... but at the end of the day the responsibility lies squarely with the main political actors," Ben Omar told al-Jazeera.

Ben Omar also referred to "obstructions" on the part of the previous regime of Ali Abdullah Saleh, who left power in 2011, for the failure of the transitional process.

Ben Omar had become increasingly unpopular among political factions in Yemen, some of whom accused him of appeasing the Houthis, and by last week it was apparent that Saudi Arabia and its allies did not want him to remain.

"We continue to support the mission of the special adviser to the secretary-general... Whoever the secretary-general designates as his special adviser, for the time being Jamal Ben Omar, yes," the Saudi ambassador to the UN, Abdallah al-Mousallimi, said on Thursday.

Fourth week of air war

Overnight, coalition aircraft hit Houthi-Saleh positions in Aden, where the forces, now officially sanctioned by the UN after a vote earlier this week, are fighting locals in an attempt to take the southern city.

At least eight Houthi-Saleh soldiers were reported killed.

In Riyadh, Khaled Bahah, Yemen's vice-president in exile, said that elite army units loyal to Saleh should support what he termed "the legitimate government" of his boss, Abd Rabbo Mansour Hadi.

The humanitarian situation continues to deteriorate across the country, with Yemen under an effective naval and air blockade.

The Iraqi prime minister, Haider al-Abadi, said there was "no logic" to the Saudi operation.

"We don't know what the Saudis want to do after this. Is Iraq within their radar? That's very dangerous. The idea that you intervene in another state unprovoked just for regional ambition is wrong."

The Saudi ambassador to the US, Adel al-Jubeir, said Abadi's comments had "no logic".