President flees amid Yemen chaos
Yemen's embattled president has fled his palace in Aden for an undisclosed location as Shia rebels offered a cash bounty for his capture and arrested his defence minister.
Yemeni president Abed Rabbo Mansour Hadi left just hours after the rebels' own television station claimed they seized an air base where US troops and Europeans advised the country in its fight against al-Qaida militants.
That air base is only 35 miles away from Aden, the port city where Mr Hadi had established a temporary capital.
The advance of the Shia rebels, empowered by backing of the ousted Yemeni autocrat Ali Abdullah Saleh's loyalists, threatens to plunge the Arab world's poorest country into a civil war that could draw in its Gulf neighbours.
Already, Mr Hadi has asked the United Nations to authorise a foreign military intervention in the country.
Witnesses said they saw a convoy of presidential vehicles leaving Mr Hadi's palace, located at the top of a hill in Aden overlooking the Arabian Sea.
Presidential officials said Mr Hadi was in an operations room overseeing his forces' response, but declined to give its location.
Yemen's foreign minister Riad Yassin told Dubai-based Al-Arabiya TV satellite news network that he had officially made a request to the Arab League on Wednesday to send a military force to intervene against Houthis.
Mr Yassin is attending the Arab Summit due to take place in Egypt at the end of the week.
Depicting the Houthis as a proxy of Shia Iran, a rival to Sunni Gulf countries, Mr Yassin warned of an Iranian "takeover" of Yemen. The Houthis deny they are backed by Iran.
Yemen's state television broadcaster, controlled by Houthis, made an offer of nearly 100,000 dollars (£67,000) for Hadi's capture.
Officials meanwhile said that the country's defence minister Maj Gen Mahmoud al-Subaihi and his top aide were arrested in the southern city of Lahj, where fighting with Houthi forces was ongoing, before they were transferred to Sanaa.
Already, military officials said militias and military units loyal to Mr Hadi had "fragmented," speeding the rebel advance. They said the rebels were fighting Mr Hadi's allied forces on five different fronts.
Mohammed Abdel-Salam, a spokesman for the Houthis, said that their forces were not aiming to "occupy" the south.
"They will be in Aden in few hours," Mr Abdel-Salam told the Houthis' satellite Al-Masirah news channel.
Al-Masirah reported that the Houthis and allied fighters had "secured" the al-Annad air base, the country's largest. It claimed the base had been looted by both al-Qaida fighters and troops loyal to Mr Hadi.
The reported Houthi takeover of the base took place after clashes between rival forces around the base. The US recently evacuated some 100 soldiers, including Special Forces commandos, from the base after al Qaida briefly seized a nearby city. Britain also evacuated soldiers.
The base was crucial in the US drone campaign against al Qaida in the Arabian Peninsula, which America considers to be the most dangerous branch of the terror group.
American and European military advisers there also offered logistical in its fight against the al Qaida group, which holds territory in eastern Yemen and has claimed directed the recent attack against the French satirical magazine Charlie Hebdo in Paris.
US operations against the militants have been scaled back dramatically amid the chaos in Yemen.
US officials have said CIA drone strikes will continue in the country, though there will be fewer of them. The agency's ability to collect intelligence on the ground in Yemen, while not completely gone, is also much diminished.
The takeover of the base is part of the wider offensive led by Houthis and loyalists of Mr Saleh within Yemen's armed forces.
The Houthis, in the aftermath of suicide bombings in Sanaa last week that killed at least 137 people, ordered a general mobilisation of its forces.
The group's leader, Abdel-Malik al-Houthi, vowed to send his forces to the south under the context of fighting al Qaida and militant groups.
The Houthis seized the capital, Sanaa, in September and have been advancing south alongside forces loyal to Mr Saleh.
On Tuesday, Houthi militias and allied forces fired bullets and tear gas to disperse thousands of protesters in the city of Taiz, known as the gateway to southern Yemen. The Houthis killed six demonstrators and wounded scores more, authorities said.
The Houthis also battled militias loyal to Mr Hadi in the city of al-Dhalea adjacent to Taiz, which is Yemen's third-largest city.
The city also is the birthplace of its 2011 Arab Spring-inspired uprising that forced Mr Saleh to hand over power to Mr Hadi in a deal brokered by the UN and Gulf countries.
Mr Hadi on Tuesday asked the UN Security Council to authorise a military intervention "to protect Yemen and to deter the Houthi aggression expected to occur at any hour from now" against Aden and the rest of the south.
In a letter to the council's president, Mr Hadi said he also has asked members of the six-nation Gulf Cooperation Council and the Arab League for immediate help.
Saudi Arabia warned that "if the Houthi coup does not end peacefully, we will take the necessary measures for this crisis to protect the region".
Diplomatic missions of Hadi's Arab Gulf allies, including Saudi Arabia, the United Arab Emirates and Kuwait, have evacuated their diplomatic staff from Aden over the past few days, officials said.
They earlier evacuated from Sanaa and relocated to Aden to support Mr Hadi.