Public discontent has mounted over the reforms that slashed subsidies on petrol and diesel, more than doubling their price.
The dozens who had gathered in Khartoum burned tyres and brandished banners that read "Bread for the poor", before they were dispersed by police who fired tear gas, an AFP correspondent reported.
Security forces also used tear gas on protesters in Omdurman, the capital's twin city across the Nile, who attempted to join the demonstrations in Khartoum.
