Yemen talks hit by walkouts over Houthi 'threats'
Crisis talks between Yemen's political factions resumed on Monday, but two parties quickly withdrew citing "threats" from Shia Houthi rebels.
The UN organised the meeting after the rebels declared that they had formed a "presidential council" to rule.
But soon after the talks began, representatives of the Nasserite and Islah parties walked out.
They complained that the Houthis had threatened to use force to compel others to accept their plan.
The Houthis have taken over large parts of the country in the past year, advancing from their stronghold in the far north and overrunning the capital Sanaa in September.
In January, the rebels seized the presidential palace complex and placed President Abdrabbuh Mansour Hadi under effective house arrest, which prompted his resignation as well as that of his entire cabinet.
The UN's special envoy to Yemen, Jamal Benomar, subsequently organised negotiations between the Houthis and the main political factions, but they collapsed on Thursday.
The following day, the Houthis announced that they would impose their own political solution to end the stand-off.
They declared that parliament would be dissolved and replaced by an interim assembly that would elect a five-member presidential council to govern for a transitional period of up to two years.
Most factions denounced the plan and the six-nation Gulf Cooperation Council (GCC) accused the rebels of staging a "coup". UN Secretary General Ban Ki-moon said Mr Hadi would have to be restored to the presidency.
The latest round of talks began on Monday after the UN warned it would take unspecified further steps against the rebels if they refused to return to the negotiating table.
However, they quickly descended into arguments between party representatives and one of the Houthis' delegates, Mehdi al-Meshaat.
According to the New York Times, Mr Meshaat was quoted by a participant as warning the parties: "If you don't behave, we will take appropriate measures against you."
The main Sunni Islamist party Islah, whose supporters have fought battles with the rebels, and the smaller Nasserite Organisation promptly withdrew, complaining of "threats".
Nasserite leader Abdullah al-Noman claimed the Houthis intended to "impose the choices of the group by force".
But Mr Benomar said the parties had agreed to reconvene on Tuesday.
"The talks took place in a constructive atmosphere characterized by mutual respect, even though animated at the outset, which is not an unusual occurrence in consultations of this nature," he added.
Yemen has been riven by instability since protesters inspired by the Arab Spring forced longtime President Ali Abdullah Saleh to hand over power to Mr Hadi in 2011.