Protesters opposed to military rule on Saturday reached the vicinity of the presidential palace in the capital of Khartoum for the second time in a week, television images showed, despite heavy tear gas and a communications black out.
A Reuters witness said Sudanese security forces fired tear gas to disperse the crowds on a tenth day of major demonstrations since an Oct. 25 coup.
Protests have continued even after Abdalla Hamdok was reinstated as prime minister last month.
A week ago, demonstrators managed to begin a sit-in at the gates of the palace, but on Saturday they were met with rows of security forces.
Internet services were disrupted in the capital, Khartoum, and locals were unable to make or receive domestic calls on Saturday, the witnesses said, while soldiers and Rapid Support Forces blocked roads leading to bridges linking Khartoum with Omdurman, its sister city across the Nile river.
People still managed to post images on social media showing protests taking place in several other cities including Madani and Atbara.
In neighboring Omdurman, security forces also fired tear gas at protesters around 2 kilometers (1.24 miles) away from a bridge connecting the city to central Khartoum, another Reuters witness said.
'Chaos and abuses'
The SUNA state news agency reported that the province of Khartoum closed bridges on Friday evening in anticipation of the protests.
"Departing from peacefulness, approaching and infringing on sovereign and strategic sites in central Khartoum is a violation of the laws," SUNA reported, citing a provincial security coordination committee.
"Chaos and abuses will be dealt with," it added.
The demonstrators have demanded that the military has no role in government during a transition to free elections
Protesters in Khartoum chanted: "Close the street! Close the bridge! Burhan will come straight to you," referring to military leader and sovereign council head Abdel Fattah al-Burhan.
They were also heard cheering when security forces fired tear gas, a Reuters witness said.
A senior official at one internet provider told Reuters the service disruption followed a decision by the National Telecommunication Corporation, which oversees the sector.
UN Special Representative to Sudan Volker Perthes urged Sudanese authorities not to stand in the way of Saturday's planned demonstrations.
"Freedom of expression is a human right. This includes full access to the Internet. According to international conventions, no one should be arrested for intent to protest peacefully," Perthes said.
The military could not immediately be reached for comment.
In Darfur, Governor Minni Minnawi asked citizens to stop looting the offices of UNAMID peacekeepers late on Friday, with sources telling Reuters they heard gunshots in the vicinity on Saturday morning.
Last Sunday, hundreds of thousands of people marched to the presidential palace and the security forces fired volleys of tear gas and stun grenades as they dispersed protesters who had been trying to organize a sit-in.
Forty-eight people have been killed in crackdowns on protests since the coup, the Central Committee of Sudanese Doctors said.