Thousands of people prayed on Friday outside the defense ministry in Khartoum, site of a massive anti-government sit-in that has continued unabated even after the military removed President Omar al-Bashir from power two weeks ago.
The sit-in, the culmination of months of demonstrations against Bashir's three-decade rule, began on April 6 but was not halted after the army removed Bashir from power on April 11.
Protesters are now demanding the restoration of civilian rule.
Friday's prayer was led by Matar Younis, a 49-year-old blind religious teacher from the Darfur region who was repeatedly jailed under Bashir.
"We call for a democratic, civilian state," Younis told Reuters. "We reject military rule. The role of the military is to protect the country, not rule the country."
The opposition is demanding a quick handover to democracy from the Transitional Military Council (TMC) which took over after removing Bashir.
Reuters estimated that 20,000 people took part in the Friday prayer outside the defense ministry. A larger than usual share of them were elderly, dressed in traditional white robes.
Younis told Reuters he wanted women and young people to participate in governing Sudan.
"Women and young people are the ones who led the revolution," he said.
Last year, while Younis was imprisoned, Amnesty International called for his release, saying he was detained for calling for the protection of displaced people from Darfur and standing up for human rights.
Bashir is wanted by the International Criminal Court over allegations of genocide in the Darfur region, charges he denies.
After the prayer, protesters chanted "civilian, civilian," referring to their demand for civilian rule. Some distributed free juice to the protesters who had showed up despite of temperatures exceeding 40 degrees Celsius (104 F). Musicians dressed in clothes made from animal skin sang folklore songs.
"We will defend democracy and refuse military rule," said Mahgoub Bushra, a 45-year-old accountant who brought his two young children to the protest site. "The people of the revolution died and were imprisoned and tortured for the sake of democracy not for the sake of military rule."
On Thursday night, hundreds of thousands also massed outside the defense ministry to demand civilian rule. The protesters were responding to a call by the Sudanese Professionals' Association (SPA), the main protest organizer, for a million people to join the march.
This followed an announcement from the TMC saying it would retain "sovereign authority," while all ministry posts, including the prime ministry, would be headed by civilians.