SANAA, Yemen -- A United Nations-sponsored Yemeni peace conference that was to start Thursday in Geneva has been indefinitely postponed, officials said.
The talks were meant to end weeks of heavy fighting and Saudi-led airstrikes against an Iran-backed rebel group amid a humanitarian crisis that has left millions in the Arab world's poorest country short of food and fuel.
Three officials from the Houthi, socialist and unionist parties said late Sunday they were notified the talks had been postponed and that no new date had been set. All the officials spoke on condition of anonymity because they were not authorized to speak to journalists.
A U.N. official, who was not authorized to discuss the matter publicly and therefore also spoke on condition of anonymity, confirmed that the talks would be postponed.
The setback came as Saudi-led warplanes on Monday pounded Shiite Houthi rebel positions in the capital and across the country.
The U.N. had urged all parties to attend the talks, announced last week, without preconditions. But the exiled government of President Abed Rabbo Mansour Hadi reiterated its demand that the Houthis first pull out of cities and towns seized in recent months, including the capital, Sanaa.
The Houthis backed the talks and said they would participate. Houthi rebel leader Abdul-Malek al-Houthi had described talks as the only solution to the war. He boycotted an earlier conference hosted by Saudi Arabia, demanding that peace negotiations be held in a neutral country.
The talks were the first major initiative of the new U.N. special envoy for Yemen, Ismail Ould Cheikh Ahmed, who this month held meetings in Yemen with rival political players. Farhan Haq, the deputy spokesman for the U.N. secretary-general, told reporters Thursday that Ahmed "believes he has the assurances he has to proceed" with the talks.
Saudi-led airstrikes began March 26. Fighting on the ground has pitted Hadi's forces against the Houthis and military units loyal to ousted President Ali Abdullah Saleh.
The Saudi-led coalition has portrayed the Houthis as a proxy for an expansionist Shiite Iran. Iran supports the Houthis but denies arming them.
Warplanes fired missiles overnight at several army camps and weapon depots in Sanaa, the capital, in the northern Houthi stronghold of Saada and in the southern city of Aden. The airstrikes came a day after some of the heaviest bombardment carried out by the Saudi-led coalition in Sanaa.
The U.N. estimates that at least 1,037 civilians, including 130 women and 234 children, have been killed between March 26 and May 20. The cities of Saada and Aden have endured the most extensive damage to their infrastructure.
Humanitarian groups have said a five-day truce that ended last week was hardly enough to get aid in. The cease-fire was breached several times.