GENEVA: Iran-backed Yemeni rebels Tuesday refused to talk with members of the exiled government attending peace negotiations in Geneva saying they lacked "legitimacy."

"We refuse any dialogue with those who have no legitimacy," rebel member Mohammad Zubairi told reporters, adding that they wanted talks instead with Saudi Arabia, which has been leading an aerial campaign against the rebels since March 26.

A Yemeni rebel delegation arrived in Geneva Tuesday for the second day of UN-backed peace talks after being stranded in Djibouti for a day, a U.N. source said.

The rebels' absence at the start of the high stakes talks that were launched on Monday by U.N. chief Ban Ki-moon had raised concerns about the negotiations.

The rebels' plane had left the Yemen capital Sanaa Sunday afternoon but was forced to wait in Djibouti for nearly 24 hours. 

The Iran-backed rebels accuse Egypt and Sudan of not allowing their plane to fly over their airspace.

Mohamed Abdel Salam, the spokesman for the Ansarullah rebel group, put up a post on Facebook thanking Oman for using "its good offices" to resolve the problem.

Oman is the only Gulf monarchy that has not joined the Saudi-led Arab coalition which launched air strikes on Yemen on March 26. 

Yemen has been wracked by conflict between Iran-backed Shiite rebels and exiled President Abed Rabbou Mansour Hadi's internationally recognized government.

Global powers are keen for a speedy resolution, fearing the growing power of Al-Qaeda in the Arabian Peninsula, the Yemeni branch of the jihadinetwork that has taken advantage of the chaos to seize territory.

On Monday, Ban underscored the need for an immediate humanitarian truce in Yemen for at least two weeks to mark the holy Muslim month of Ramadan in order to furnish critical supplies to millions of people facing acute shortages.

The U.N. chief held talks with a government delegation but regretted not being able to meet the rebels.

The U.N. has described Yemen's humanitarian crisis as "catastrophic," with 80 percent of the population - 20 million people - in need of aid.

The rebels, supported by military units loyal to ex-president Ali Abdullah Saleh, have seized control of large parts of the country including the capital Sanaa, forcing president Hadi to flee to Saudi Arabia in February.

The second day of the talks coincide with reports, confirmed by Al-Qaeda in Yemen, that its leader Nasir al-Wuhayshi, number two in the global jihadi organisation, was killed in a US drone strike.

Washington has not yet commented on the death of Wuhayshi, whose group, Al-Qaeda in the Arabian Peninsula, has been behind several plots against the United States.