By Carl Odera
NAIROBI (Reuters) - Peace talks with South Sudan's rebels have been delayed again, the government said on Tuesday, a day after the United Nations accused rebel fighters of massacring civilians in an oil town they had seized.
"The talks have been postponed," Information Minister Michael Makuei told Reuters by telephone. "The reason (the mediators) gave is that it will give them the opportunity to make further consultations."
Negotiations between the government of President Salva Kiir and rebels loyal to former vice president Riek Machar have failed to advance since the January 23 signing of a ceasefire which never took hold.
The killing of hundreds of men, women and children in the oil hub of Bentiu, which was seized by the rebels a week ago, has exacerbated ethnic tensions between Kiir's Dinka people and Machar's Nuer. The rebels deny they carried out the killings.
A U.N. official told Reuters she had seen dozens of rotting bodies strewn in Bentiu's dusty streets.
"(In) the market place we saw large piles of bodies, dozens and dozens of bodies, piled up on top of each other," said Amanda Weyler, communications officer for the U.N. humanitarian coordination office OCHA. Women were among the dead, she said.
The United Nations said on Monday that rebels had killed civilians as they sought refuge in a hospital, a mosque and a church.
The rebels said the U.N. allegations were baseless and accused a part of the U.N. mission in South Sudan of pedaling "cheap propaganda" to win favor with Kiir, blaming government forces for the systematic killings.
"The government forces and their allies committed these heinous crimes while retreating," rebel spokesman Lul Ruai Koang said in an emailed statement. These are ridiculous allegations fabricated by enemies of (the) war of resistance for democratic reforms."
The East African IGAD group brokering the talks postponed their resumption by five days to April 28, the government said.
More than 1 million people have fled their homes since fighting erupted in the world's youngest country in December.
Thousands of people have been killed and tens of thousands have sought refuge at U.N. bases around the country after the violence spread across the country the size of France and took on an ethnic dimension.
(Writing by Richard Lough; Editing by Robin Pomeroy)