Protest leaders in Sudan have announced plans to present a civilian body to take over from the ruling military council.

The development came as demonstrators gathered outside army headquarters in the capital Khartoum and the United States said it would send an envoy to encourage the transition.

The military council, which took power after ousting longtime leader Omar al-Bashir on 11 April, has so far resisted calls from protesters to quickly make way for a civilian administration.

The Sudanese Professionals Association, which has been spearheading the protests, said in a statement that it would name members of the council at a news conference on Sunday outside the army complex, to which foreign diplomats are also invited.

"We are demanding that this civilian council, which will have representatives of the army, replace the military council," Ahmed al-Rabia, a leader of the umbrella group of unions for doctors, engineers and teachers, said.

Today marks four months to the day since the government tripled the price of bread, sparking the first protests which escalated into widespread rallies demanding Mr Bashir's departure.

Access roads were packed, with crowds flocking to huge square outside army headquarters to offer the weekly Muslim prayers.

"This government should be a representative of all the people and their aspirations," said prominent cleric Sheikh Mater Younis as he addressed thousands of protesters after the weekly Muslim prayers at the army complex.

Protester Yasser Dahab said all who had committed crimes against the Sudanese people should be put on trial.

He said he wanted to see a civilian council with a prime minister and a government led by technocrats.

"This government can then prepare for free elections in two years with participation from all parties," Mr Dahab said. "The military should stay away from political life."

Activists had called for large crowds to gather after weekly Muslim prayers, as on previous Fridays.

Following the ousting of Mr Bashir, demonstrations targeted General Awad Ibn Ouf, the first head of the military council, seen by protesters as a tool of the old regime.

General Ibn Ouf stepped down in less than 24 hours and was replaced by General Abdel Fattah al-Burhan, who so far has appeased protesters by lifting a night-time curfew and vowing to "uproot" Mr Bashir's circle.

US sends diplomat to Sudan

The US has praised orders by Sudan's new military leader to free political prisoners and end the curfew.

It has also dispatched Makila James, a deputy assistant secretary of state, on a mission to the country this weekend.

The US will "calibrate our policies based on our assessment of events", State Department spokeswoman Morgan Ortagus said, but added that talks on delisting Sudan as a state sponsor of terrorism remain suspended.

She welcomed the release of political prisoners but urged the military to "show restraint, avoid conflict and remain committed to the protection of the Sudanese people".

She added: "The will of the Sudanese people is clear: it is time to move toward a transitional government that is inclusive and respectful of human rights and the rule of law".