Sudan's main protest group called on Tuesday for a general strike, saying two late-night negotiation sessions with the army had failed to reach a deal on how to lead the country after the overthrow of former president Omar al-Bashir.
An alliance of protest and opposition organisations is demanding civilians head a new Sovereign Council which is meant to oversee a three-year transition towards democracy.
But the Sudanese Professionals Association (SPA) protest group said the army was still insisting on directing the transition and keeping a military majority on the council.
"Civilian power means that the structure is fully civilian with a civilian majority in all its parts," the SPA said in a statement. It said members should mobilise for a strike, without giving a date.
The impasse has hit hopes of a quick recovery from the political turmoil that climaxed in the end of Bashir's three-decade rule on April 11.
The army ousted the former general after months of protests against soaring prices, cash shortages and other economic hardships.
It set up a Transitional Military Council (TMC) to rule the country and promised to hand over after elections.
But, wary of the example of neighbouring Egypt where the head of the army eventually became president after the overthrow of Hosni Mubarak, Sudanese protesters have sought guarantees of civilian control.
The army acknowledged early on Tuesday that the make-up of the sovereign council remained the main point of contention, but did not go into details on its position.
"Aware of our historical responsibility, we will work toward reaching an urgent agreement ... that meets the aspirations of the Sudanese people and the goals of the glorious December revolution," said a statement signed by the TMC.
It gave no date for when talks would resume.
Various powers including wealthy Gulf Arab states are trying to influence the path of a country of 40 million strategically located between the Middle East and sub-Saharan Africa in a volatile region.
