Sudanese marched on the army headquarters in Khartoum Thursday, in a million-strong rally demanding a civilian administration as talks with the country's military rulers remained deadlocked.
The protesters have been holding negotiations with the transitional military council over the creation of a new sovereign council, but the two sides remain divided over how large a role the generals should have in it.
The army has been pushing for a 10-member council including seven military representatives and three civilians.
The coalition is demanding a council made up of eight civilians and seven generals.
The protesters fear the military intends to hold onto power or cut a deal with other factions that would leave much of ousted President Omar al-Bashir's regime intact.
Protest leaders from the Alliance for Freedom and Change say the generals are not serious about handing power to civilians.
The disagreement prompted the alliance to announce the "million-strong march to assert our main demand, which is for civilian rule".
The call has exacerbated tensions between the two sides.
Protest leaders Thursday handed the military council proposals for the new civilian structures they want to see rule the country eventually, including executive and legislative bodies.
As the wrangling persisted, the crowds flocked to the army headquarters in central Khartoum to join the thousands who have remained camped there round-the-clock for weeks.
People came from a number of different provinces to join the march, a Reuters witness said.
The military council has warned it will not allow "chaos" and urged protesters to dismantle makeshift barricades they have set up around the location.
It also demanded demonstrators open roads and bridges that have remained blocked as rallies continue in the wake of Bashir's departure.
