Two Sudanese men have been killed on Thursday as the country saw its most widespread protests during more than a month of unrest.
The Sudanese Doctors' Committee said in a statement that medical student Mahjoub al-Taj Majhoub died "after being subjected to beating and torture" while in police custody.
University student Abd al-Azeem Babikir, 22 was killed "after a bullet hit him directly in the chest."
The government confirmed a 24-year-old man had died, taking the official number of protesters killed to 29 - though human rights groups say more than 40 have been killed.
A raft of live feeds from various cities have been continuously broadcast during the day showing large crowds around the country and some of them depicting protesters bleeding from what they said were bullet wounds.
According to the Sudanese Professionals Association (SPA), which has organised regular protests, more than 40 areas in Sudan demonstrated on Thursday.
A military source told MEE, on condition of anonymity, that a member of the intelligence agencies was killed overnight Wednesday.
An eyewitness in Port Sudan, Ali Abdo, told MEE that the army expelled the National Intelligence and Security Services (NISS) forces, which have been widely used to crack down on protesters, from the city.
“Now the army is in full control of the city and the security organs have disappeared from the city,” he added.
An activist from the city, who did not want to be named, told MEE they believed the disagreement was because the army had previously protected protesters.
“What happened is a small coup against the control of the security organs [NISS], now the army has shown its strength and that's a serious sign if it is be replicated in other parts of the country,” the activist said.
Police said Thursday that commanders of both groups later stopped the fighting and the situation was "under control".
However, another eyewitness in the capital Khartoum said there had also been disagreements between the police in the flashpoint neighbourhood of Burri and NISS forces.
“The police have made a cordon around the area, preventing the security services from entering the houses,” the witness said.
Three people, including a doctor, were killed in Burri last week, prompting thousands to attend their funerals last Friday.
The demonstrations that were initially fuelled by anger over a hike in living costs morphed into direct protests against the government and are seen as the biggest threat to President Omar al-Bashir's rule since he took power in a 1989 coup.
The SPA had called for nationwide rallies on Thursday.
"We are calling our people to gather at 17 places in Khartoum and Omdurman and march towards the presidential palace," the association said in a statement.
Protesters have staged daily demonstrations in Khartoum and the capital's twin city of Omdurman, on the west bank of the Nile river.
On Thursday, hundreds of protesters began demonstrating in Burri, only to be confronted by riot police with teargas, witnesses said.
"Let's die like martyrs or fight for their rights," shouted men and women as they took to the streets in Khartoum, witnesses said.
Riot police also fired tear gas at protesters in Omdurman, and rallies reported in the state of Gezira, the Red Sea town of Port Sudan and a village in North State, witnesses said. Economic crisis
Several previous attempted marches on the presidential palace have been broken up by riot police firing tear gas.
Several corporates and business outlets in Khartoum ordered their employees to leave before the protests began, while many schools saw few children attending classes.
Protests have also been called on Thursday in other towns and cities, said the SPA, an umbrella group of unions representing doctors, teachers and engineers.
The hike in the price of bread brought demonstrators onto the streets of the eastern farming hub of Atbara and other provincial towns on 19 December.
The protests then rapidly spread to the capital Khartoum and other big cities as people vented their anger against the government.
The demonstrations come with Sudan battling an economic crisis driven by soaring inflation and a shortage of foreign currency.
Bashir, 75, has remained defiant and rejected the calls to step down. He has blamed the violence on "infiltrators" among the protesters.
The veteran leader has accused the United States of causing Sudan's economic woes, but his words have fallen on increasingly deaf ears as people have struggled to buy even basic foods and medicines.
The United States imposed a trade embargo on Sudan in 1997, and it was lifted only in October 2017.