Sudan's military rulers said on Monday evening that they are communicating with all political forces to name a prime minister and form a civilian government "as soon as possible".
A military spokesperson, Lieutenant General Shamseldin Kibashi, made a brief announcement on state TV but did not comment directly on protest organisers' demands from a day earlier for the immediate transfer to a civilian government.
Tensions escalated after talks broke down on Sunday between protesters and the military council, which has ruled the country since President Omar al-Bashir was forced from office April 11 after nearly four months of mass protests against his 30-year rule.
The protesters have rallied outside the military headquarters in Khartoum since April 6, and remained in place despite the military's call on Monday morning for the reopening of roads blocked by sit-ins established during the uprising that drove al-Bashir from power. The military asked that other roads, closed by similar protests across the country, also be opened.
Thousands of people participated in demonstrations on Monday in other cities. Videos showed hundreds of high school students marching in Port Sudan on the Red Sea and shouting "Revolution". Other footage showed thousands of protesters outside a military complex in the province of Sennar, about 360km east of Khartoum.
In a strongly worded statement, the large opposition Umma Party warned the military council against "attempts by some of its members to reproduce" al-Bashir's regime. It called for an "immediate" transfer of power to the forces behind the protests.
Protest organisers on Sunday suspended talks with the military council, saying it would not agree to immediate civilian rule. Spokesperson Mohammed al-Amin Abdel Aziz said the military council was "delaying its response to our proposals, saying that they are considering proposals from all political forces".
This has raised fears among protesters that Islamists and other factions close to al-Bashir, who is now jailed in Khartoum, will have a role in the transition. They fear that could leave much of his regime intact or pave the way for another strongman.
The Sudanese Professionals Association, which has led the protests, is calling for a Cabinet of technocrats to run the country's daily affairs. They want a legislative council, in which at least 40% of the membership would be women, to draft laws and oversee the Cabinet until a new constitution is written.
The association has vowed to carry on with sit-ins. The umbrella group of professional unions called for a march on Tuesday and for mass rallies on Thursday, when it plans to announce its own civilian transitional council in a challenge to the military.
Large crowds gathered outside the military headquarters on Sunday night, singing and dancing as protest leaders delivered fiery speeches. Qurashi Diefallah, a protester, said the army is "just an extension of the regime, which stole 30 years from us".
General Abdel-Fattah Burhan, the head of the military council, said on Sunday that it would hand over power immediately to a "civilian government agreed by all political forces".
Burhan said the council had received "more than 100 visions" from various political factions for the future the county, including that of the protest organisers. He said the military would respond to proposals within a week.
Those remarks angered the protesters, who saw them as an effort to sideline the Sudanese Professionals Association by portraying it as one of many political factions.
Hani Raslan, an expert on Sudan at the Al-Ahram Centre for Political and Strategic Studies in Cairo, said the inclusion of figures once close to al-Bashir in the military council and its outreach to political parties that had taken part in a national dialogue with al-Bashir, angered protesters.
"The protesters say the council, by these actions, is reproducing the old regime," he said. "The council could accelerate some measures against al-Bashir's regime to calm down the situation and get the SPA back to the negotiation table.