Tens of thousands of people took to the streets in Khartoum on Sunday demanding the ruling Transitional Military Council (TMC) hand over power to civilians, in the largest demonstrations since security services evacuated a protest camp outside the headquartes of the armed forces in the capital three weeks ago.
Protesters waved the Sudanese flag and chanted "civilian, civilian" in several parts of the capital as security forces looked on.
Opposition groups posted videos of what they said were rallies in other cities.
Sudan’s TMC overthrew president Omar al-Bashir on April 11 after months of demonstrations against his 30-year-rule.
Opposition groups kept up their streets protests as they pressed the TMC hand over power to civilians.
Talks broke down and protests paused after security services evacuated a sit-in protest outside the defence ministry on June 3, leaving rens killed or injured.
But there has been a run of smaller demonstrations in recent days, and the Forces for Freedom and Change (FFC) opposition coalition called for a million people to turn out on Sunday.
There was no immediate comment from the ruling military council which had warned a day earlier that the coalition would bear the responsibility for any loss of life or damage resulting from the rallies.
Members of one of the main opposition groups - the Sudanese Professionals' Association - said security services raided its headquarters on Saturday night as it was about to give a news conference.
The United Nations has said it has received reports that more than 100 protesters were killed and many more injured at the sit-in protest on June 3.
The TMC leaders have denied ordering a raid on the camp and said a crackdown on criminals nearby had spilled over to the sit-in.
The council has said some officers had been detained for presumed responsibility and it still intends to hand over power after elections.
Mediators led by the African Union and Ethiopian Prime Minister Abiy Ahmed have since been trying to broker a return to direct talks.
*This story was edited by Ahram Online