Sanaa: Yemeni political factions resumed UN-brokered talks on Monday with the Shiite militia that grabbed power last week, but one group walked out underlining the complexity of the crisis.
"We will not return to the table of negotiations," Nasserite party chief Abdullah Nooman told reporters as he left the closed-door meeting in the capital Sanaa.
Nooman charged that the Huthi militia was insisting on holding talks based on the "constitutional declaration" under which they took over the government on Friday.
The Huthis "have threatened to take measures" against the Nasserite party and Al-Islah, a Sunni Islamist party whose supporters have battled the Shiite militia, he added.
Al-Islah and the Nasserite party have both rejected the Huthi power grab and called for a return to political dialogue.
On Friday, the militia dissolved parliament and created a "presidential council" in a move it said was designed to fill a power vacuum after Western-backed President Abedrabbo Mansour Hadi and Prime Minister Khalid Bahah resigned last month.
The militia also sought to portray the move as a way of heading off the threat from Al-Qaeda, which has a strong presence in southern and eastern Yemen.
UN envoy Jamal Benomar told reporters Sunday that Shiite militia leader "Abdelmalek al-Huthi and all political parties in Yemen have agreed to resume dialogue... which will begin tomorrow (Monday)".
Benomar called on all political leaders to "take up their responsibilities and achieve consensus" in order to reach a "peaceful solution".
On Monday, he addressed the meeting at a Sanaa hotel saying: "The dialogue resumes from where it stopped on Thursday."
The takeover of the government the following day by the Huthis, who have controlled the capital since last September, has drawn international condemnation, with UN chief Ban Ki-moon calling on Sunday for Hadi to be restored to power.
"The situation is very, very seriously deteriorating, with the Huthis taking power and making this government vacuum. There must be restoration of legitimacy of President Hadi," Ban said.
The fall of Hadi`s government has sparked fears that impoverished Yemen -- strategically located next to oil-rich Saudi Arabia and on the key shipping route from the Suez Canal to the Gulf -- could plunge into chaos.
Yemen, a deeply tribal country awash with weapons, has been riven by crisis since veteran strongman Ali Abdullah Saleh was forced from power in 2012 following a bloody year-long uprising against his rule.
The country is also facing a separatist movement in the formerly independent south.