Sudanese protest leaders raised the pressure on the country's army rulers on Wednesday, threatening a general strike and calling for a million-strong march to demand a civilian government.
The military council that took power after veteran president Omar al-Bashir was ousted earlier this month meanwhile invited rally leaders to a new meeting.
Siddiq Farouk, one of those spearheading the protests, told reporters the demonstrators were "preparing for a general strike" across the country if the army rulers refuse to hand power to a civilian administration.
He also said that a "million-strong march" is planned, confirming a call for the mammoth protest Thursday by the Sudanese Professionals Association (SPA), the group that launched protests against Bashir in December.
For the first time, Sudanese judges said they would join a sit-in outside army headquarters "to support change and for an independent judiciary".
The demonstrations began in the central town of Atbara on December 19 against a decision by Bashir's government to triple bread prices.
They swiftly turned into nationwide demonstrations against his rule and that of the military council that took his place.
The council, led by General Abdel Fattah al-Burhan since his predecessor quit after barely 24 hours in the post, says it has assumed power for a two-year transitional period.
Hundreds of protesters came from the central town of Madani to join the sit in on Wednesday, the second major batch of new arrivals from outside the capital in as many days.
A train laden with demonstrators had rolled in from Atbara -- the crucible of the protests -- on Tuesday.
"We have come from Madani and we demand civilian rule!", the latest arrivals chanted.
"Revolutionaries from Madani want civilian rule," they also belted out, according to witnesses.
The protesters suspended talks with the council on Sunday over its refusal to transfer power immediately.
The military council said it had invited the protest leaders to another meeting on Wednesday evening at the presidential palace.
The council acknowledged the role of the protest alliance in "initiating the revolution and leading the movement in a peaceful way until the toppling of the regime" of long-time leader Omar al-Bashir.
"The council is hoping that the outcome of the meeting ... will lead to resuming of talks with this umbrella group concerning the future of our homeland," the military said in a statement.
Earlier in a press conference senior opposition figure Omar el-Digeir said protest leaders were prepared to meet directly with Burhan.
"We are ready to talk with the chief of the military council and I think the issue can be solved through dialogue," he told reporters.
Thousands have camped outside the military headquarters in central Khartoum since before Bashir was deposed, and have vowed not to leave the area until their demands have been met.
The protesters have found support in Washington, which has backed their call for civilian rule.
"We support the legitimate demand of the people of Sudan for a civilian-led government, and we are here to urge and to encourage parties to work together to advance that agenda as soon as possible," State Department official Makila James told AFP on Tuesday.
"The people of Sudan have made their demand very clear," she said.
On Tuesday several African leaders, who had gathered in Cairo at the behest of President Abdel Fattah al-Sisi, insisted on "the need for more time" for a transition, according to the Egyptian presidency.
The leaders urged the African Union to extend by three months an end-of-April deadline for the council to hand power to a civilian body.
But Rashid al-Sayed, a spokesman for the SPA, insisted Wednesday that "what's happening in Sudan is an internal matter".
"We are betting on the continuation of protests," he said.