According to what eyewitnesses quoted to France Press, demonstrators tried to put up barriers to block roads using tires, stones and logs, but riot police prevented them by firing tear gas.
The witness confirmed that the internal roads were completely closed and the protesters were trying to persuade some residents to refrain from going to work.
The movement of public transport between central Khartoum and its outskirts has slowed, while small numbers of private vehicles are moving, and shops are closed in the commercial area in the central Khartoum or the Arab market.
"A number of passengers are waiting outside the departure lounge at Khartoum airport," an AFP journalist said.
The Sudanese opposition began with civil disobedience and called for the rebellion to end only with a field government broadcasting a statement of "authority handover."
The junta took office in April after President Bashir deposed after months of protests. Since then, the military leaders have resisted calls by protesters and the international community to transfer power to a civilian administration, and several rounds of talks finally collapsed in mid-May.
The call for civil disobedience followed a visit by Ethiopian Prime Minister Abe Ahmed to Khartoum to mediate between the leaders of the protests and the military council that has ruled Sudan since the ouster of Omar al-Bashir on April 11, followed by the arrest of a number of leaders leading the demonstrations.