The Yemeni leader who resigned the presidency last month and fled to the country's south on Saturday said all actions taken since Shiite rebels stormed the capital, Sanaa, last September are illegitimate, hinting that he will seek to reclaim his power and office.

The move exacerbates worries over a regional breakup and further instability in the volatile country, the Arab world's poorest and home to a powerful al-Qaida affiliate. The rebels, known as Houthis, control Sanaa and several major cities, while the south is largely free from their rule and officials there have rejected the rebel takeover amid talk of a potential secession.

In a statement signed as "president of the republic" from the southern port city of Aden, Abed Rabbo Mansour Hadi called for a national dialogue there or in the city of Taiz, another area not under Houthi control, and demanded the rebels leave Sanaa.

He said he supports the power transfer plan backed by Gulf countries after Yemen's 2011 Arab Spring uprising, which envisaged him taking office from predecessor Ali Abdullah Saleh until elections. He also called on military and security forces to support him, and demanded the Houthis release members of his former Cabinet who are still under house arrest in Sanaa.

An official from Hadi's office, speaking on condition of anonymity because he was not authorized to brief journalists, said that Hadi had resigned during an "unnatural situation" while he was under house arrest.

He left Sanaa Saturday after the rebels who had surrounded his home for several weeks released him under international and local pressure, aides close to him said, although the rebels said later in a statement that he had made a furtive escape. Earlier, Hadi's aides said he planned to leave the country for medical treatment.

Witnesses said the Houthis and others in the area later ransacked Hadi's house and people were seen removing automatic rifles from the building. The spokesman for Yemen's embassy in Washington, Mohammed Albasha, said on Twitter that Hadi and his family had arrived safely in Aden, but that his press secretary had been detained.

Jamal Benomar, the U.N. envoy to Yemen, said Friday that rival factions, including the Houthis, had agreed on a new legislative body consisting of former and new lawmakers to serve during the country's upcoming transition period, although those prospects seemed bleak after Hadi's defiant comments.

A coalition of Yemeni parties also voiced objections to the plan, describing it as an insufficient half-solution, and later Saturday the Nasserite block demanded Hadi be returned to power.

Ahmed Lakaz, spokesman of the Unionist Gathering Party, which is taking part in the dialogue, earlier said the parties told the Houthis that they would not participate in the process until Hadi was freed.

The ongoing political crisis casts doubts on the United States' ability to continue its counter-terrorism operations in Yemen.

However, the U.S. has continued to target al-Qaida's branch in Yemen, known as al-Qaida in the Arabian Peninsula, with drone strikes. Tribal sources said Friday that two suspected al-Qaida members were killed in a drone strike in the southern province of Shabwa.

Meanwhile Saturday, Houthis tried to storm a special forces base outside the capital, exchanging fire with troops there who are mostly loyal to Hadi's predecessor Saleh. The fighting killed three people, security officials said.

Saleh's aides say he considers the base key to his survival and would never allow it to fall under Houthi control — unlike most of Sanaa's other military installations, which are already in rebel hands. Those aides spoke on condition of anonymity as Saleh had not authorized them to speak to reporters.

Thousands also marched Saturday in support of Hadi in southern Ibb province, where they urged the Houthis to leave the region and halt their interference in local affairs. The Houthis opened fire, killing one demonstrator and wounding two, said security officials, who spoke on condition of anonymity as they weren't authorized to talk to journalists.

AP