The demand to reopen roads came a day after rally leaders suspended talks with the 10-member military council.
Sudan's new army rulers on Monday ordered protesters to dismantle their barricades on roads leading to the military headquarters as tensions grew after talks between the two sides broke down.
The demand to reopen roads came a day after rally leaders suspended talks with the 10-member military council, frustrated at a lack of headway over their main demand for an immediate transfer of power to a civilian administration.
The demonstrators have accused the ruling military council of being little different from veteran leader Omar al Bashir who was toppled by the army on April 11 following months of street protests.
Protest leaders have vowed to intensify demonstrations that erupted in December, and neighbouring Egypt announced on Monday it will host an emergency summit of African leaders Tuesday on "the evolution of the situation" in Sudan.
Separately, the new head of Sudan's National Intelligence and Security Service (NISS) – a much-feared organ during Bashir's long tenure - on Monday met Egyptian President Abdel Fattah al Sisi in Cairo.
After the meeting with Abu Bakr Mustafa, the Egyptian president praised the "efforts" of Sudan's military council, according to a statement by the presidency.
He also stressed "Egypt's full and unconditional readiness to provide all means of support for Sudan".
Military 'can't be trusted'
Protesters vowed to remain at the makeshift barricades they have set up on roads leading to the main protest camp outside army headquarters in Khartoum, to frisk people coming to the rally.
"Sit-in will continue until the fall of the regime," a huge banner on a bridge at the protest site outside army headquarters in Khartoum read on Monday.
Fai Othman, a protester, vowed to resist the military council’s order to remove blockades, stressing they had been erected to protect demonstrators.
"There’s no guarantee that the military council would provide security for the protesters," she said.
"No military man can be trusted."
The protest leaders had pledged to name members of a civilian body on Sunday to take over from the military council, but by nightfall, it was clear it would not happen.
"We are suspending our talks with the military council," spokesman Mohamed al Amin told the tens of thousands of protesters gathered at the army complex.
"We call for escalating and continuing the demonstrations until the demands are met," he said.
Protesters have massed outside the army complex since April 6.
But initial jubilation at the end of Bashir's three decades of iron-fisted rule quickly turned to anger over the military council's plan to rule for a two-year transition period.
On Sunday, Sudan's new military ruler General Abdel Fattah al Burhan insisted the army rulers were "committed to giving power to (the) people," and pledged to respond to the demonstrators' demands within a week.
'Don't fear violence'
"We will carry on manning the checkpoints as usual," 23-year-old demonstrator Kawthar Hasaballah told AFP.
"No one, not even the military council, will remove us from our places."
The mood was upbeat on Monday at the rally site where a group of protesters chanted: "Burhan is dirt brought by the Kizan (Islamists)".
Protester Assad Saeed Gaber said he backed the protest leaders' decision to halt talks.
"The military council has been stalling and attempting to take over power," he said.
Fellow demonstrator Munira Mustafa al Badawi was also undeterred. "I don't fear violence. I don't think they (the army) will disperse the protest violently," he said.
Sudan's main opposition party has joined calls for the council to be dissolved and to hand power to a transitional civilian government.
"Some of the members of the military council have an agenda," the National Umma Party said in a statement.
"They want to recycle the toppled regime."
Bashir, who swept to power in a 1989 coup, was one of Africa's longest-serving presidents.
He is wanted by the International Criminal Court on charges of genocide and war crimes.
On Sunday, the new army rulers said that cash worth more than $113 million had been seized from Bashir's home during a search.
Saudi Arabia and the United Arab Emirates have offered $3 billion in financial aid to the impoverished country.
Elsewhere, NISS offices were attacked Sunday in the North Darfur town of Kotum, official news agency SUNA reported.
Eleven people, including a policeman, were wounded in ensuing clashes, it said, without giving details.