Huge crowds formed outside Sudan's defence ministry on Thursday, joining a sit-in protest to demand that the country's transitional military council hand power to civilians.
Hundreds of thousands packed the streets by early evening - the largest crowds to gather in the centre of the capital since last week, when former President Omar al-Bashir was ousted and the military council took over.
Protesters chanted "Freedom and revolution are the choice of the people" and "Civilian rule, civilian rule", and waved national flags.
Giant screens showed a film documenting apparent abuses by the security services.
"We will remain in the street until power is handed to civilian authority," said 24-year-old protester Samia Abdallah. "We will bring down military rule."
The council has said it is ready to meet some of the protesters' demands, including fighting corruption, but has indicated that it would not hand over power to protest leaders.
It has said that a transitional period of up to two years will be followed by elections and that it is ready to work with anti-Bashir activists and opposition groups to form an interim civilian government.
"We are completely committed to handing over power within a maximum two years," one of the members of the council, Lieutenant General Salah Abdelkhalek, told state TV on Thursday.
"Perhaps the most difficult issue facing the military council now through its political committee is getting agreement from the political spectrum and the community forces on the naming of a prime minister," Abdelkhalek said."The ball is in their court."
The head of the 10-man military council, Abdel Fattah al-Burhan, and his deputy are known for their ties to Saudi Arabia and the United Arab Emirates, through Sudan's participation in the Saudi-led coalition fighting Houthi rebels in Yemen.
Late on Thursday, the council's spokesman said an undersecretary at Sudan's foreign ministry had been dismissed over a statement from the ministry that had said preparations were under way for the visit of a delegation from Qatar, the regional rival of Saudi Arabia and the UAE.
Spokesman Shams El Din Kabbashi said the ministry had made the statement without consulting the council, state news agency SUNA reported.
The sit-in that began on April 6 outside the defence ministry in Khartoum was the culmination of 16 weeks of protests triggered by a worsening economic crisis in Sudan, leading to Bashir being ousted and arrested after three decades in power.
Sudanese have been struggling with sharp price rises and shortages of cash and basic products.
Many analysts blame the country's economic troubles on mismanagement, corruption and the impact of U.S. sanctions, as well as loss of oil revenue when South Sudan seceded in 2011.
In 2017 the U.S. lifted trade sanctions but kept Sudan on its state sponsors of terrorism list, depriving it of debt relief from international lenders.
On Thursday the United States expressed its support for a democratic transition in Sudan, saying it was encouraged by the release of political prisoners and the cancellation of a curfew.
It said Washington's policies toward Sudan would be based on "our assessment of events on the ground and the actions of transitional authorities."