Sudanese riot police fired tear gas at anti-government protesters in Khartoum's twin city Omdurman on Wednesday, witnesses said, after hundreds rallied in the capital in support of President Omar al-Bashir.
About 300 protesters chanting "Freedom, Peace and Justice" blocked a key road in Omdurman, but were quickly confronted with tear gas as riot police moved in to disperse them.
The earlier loyalist rally was the first held in Khartoum since anti-government protests erupted across Sudan last month.
Authorities say at least 19 people, including two security personnel have been killed during the demonstrations but human rights group Amnesty International has put the death toll at 37.
Protests broke out on December 19 after a government decision to raise the price of bread at a time when Sudan is facing a mounting economic crisis.
Food and fuel shortages have hit Sudan repeatedly over the past year as foreign currency reserves have dwindled and inflation has soared to 70 per cent.