Salah Elsir came to the protest camp outside Sudan’s military headquarters in Khartoum three days ago, riding the “freedom train” from Atbara, the birthplace in December of the country’s revolution against the regime of the former dictator, Omar al-Bashir.

A 28-year-old artist from a family of railway workers, Elsir’s brother Elshazli was one of the organisers of the train that rolled slowly into the city centre on Tuesday, its roof crowded with banner-waving activists to a reception both tearful and joyous.

While some of the 1,000 or so who came with him returned to their home city, Salah Elsir remained.

Like others crowding the tent shelters that have sprung up on the streets of Khartoum’s city centre, Elsir came from his home city – as others came in convoys from Kosti and other places outside the capital – to protect what they see as their revolution.

Joining the tens of thousands who converged again to join Khartoum’s month-old and vast protest sit-in on Thursday night, the reason for Elsir’s jouney was underlined by the latest statement from the country’s interim military council that once again raised fears that the generals, who so long dominated the country, would not give up their power and privileges so quickly.

A young Sudanese protester in Khartoum. Photograph: Ümit Bektaş/Reuters

In a rebuff to the protest movement, which has been demanding a rapid move to an interim civilian-led political transition, after 30 years of autocratic rule, Shams al-Deen al-Kabashi, a spokesman for the military council, insisted that the military will “maintain sovereign powers” until elections can be held.

“We’ve come because we want to let the military council know what the people are demanding,” said Elsir, in one of the tents that have sprung up around the city centre, many of them dedicated to people from a city or organisation. “I’m worried they don’t want to give up power to the civilians and we could be tricked. We are here to protect the revolution that started in Atbara.”

For protesters, the symbolism of the freedom train that brought activists from Atbara has been poignant, recalling a similar train sent from the city in the uprising of October 1964 against the first military dictator government.

Some saw other meanings too, recalling how the Bashir regime had targeted both the country’s crucial railway system and its workers. “In the last 30 years, the government deliberately destroyed the railway system in Sudan and impoverished the workers,” said Faisal Mohamed Salih, a political analyst and writer.

Sudanese protesters in front of a recently painted mural. Photograph: Ozan Köse/AFP/Getty Images

“Atbara is important in the Sudanese political and workers’ history, because it’s a working-class city, and it’s the capital of the railway system in Sudan founded in the British colonial period. It has always had a national role. ”

Elsir’s sentiments were echoed by Ahmed Rabie, a leader in the SPA, an umbrella of independent Sudanese unions. “This is disappointing and we did not expect to hear that. For us, this option is completely unacceptable. If the military insist on holding to sovereign powers, we will escalate our protests,” said Rabie, echoing a common theme and adding that protesters can call for a national strike and civil disobedience.

The reality is that even as three more senior generals stepped down this week in the face of the continuing protests, Sudan’s new democracy movement is facing a tough new test.

With Bashir gone, the question is no longer about his rule, even as key supporters in the security forces removed their support, sending him to Khartoum’s Kober prison.

Now, the key battleground is between the still-powerful remnants of Sudan’s old deep state and a street movement anxious to dismantle all the old laws and state structures of the Bashir era, a process, critics argue, that can only occur if civilians are in charge of the transition process.

That struggle is continuing even as some from locations like Atbara, far from the capital, are closely watching not only the manoeuvres of the military council but also keeping a wary eye on old opposition parties, and the leaders of the new opposition movement, anxious that their interests are sold out.

For now, however, the main concern is the Transitional Military Council, fronted by Lt Gen Abdel-Fattah Burhan, which has been described by some as a “decorative coup” and by others as “Bashirism” without Bashir.

Sudanese protesters outside the army headquarters in Khartoum, Sudan. Photograph: EPA

On Friday, the pressure on the military continued as thousands gathered to hear Sheikh Matter Younis, an activist from war-torn Darfur. “We will not retreat until we get our main demand of civilian rule,” insisted Younis, to chants of “freedom, freedom,” adding that those guilty of human rights abuses “have to be held accountable”.

In a nearby tent, other protesters had travelled from Kosti, five hours south of Khartoum, for the same reason, arriving in the capital in a convoy. “We arrived yesterday by bus and car,” Nimad Adam, one of many women prominent at the forefront of the protest movement, told the Guardian.

“We’re here to make sure we are part of the process. To make sure that we get a civilian interim process, led by technocrats, not the military council.”

At his house in Khartoum’s twin city of Omdurman, the analyst and activist Hafiz Mohamad, director Justice Africa Sudan, explained the continuing tension between the military and protesters.

“The problem with what the military council spokesman said yesterday is over the issue of who has right to make the laws in the interim period, at a time when we need to change all of the old laws.

“I think it is trying to deceive people. The remnants of the regime want to keep the old laws intact, but we cannot have change until we are able to reform them all: the election laws, permanent constitutional change, penal code reform. Until people have been given back their personal freedom and things like the public order act have been been repealed.

“If you want a transition to democracy, you can’t have these laws intact.”