Sudanese security forces fired tear gas and stun grenades on Friday at 300-400 protesters leaving a mosque in Omdurman, near the capital, a Reuters witness said.
Opposition groups and activists had called for large anti-government protests to take place following weekly Muslim prayers on Friday.
Ahead to the protests, the Sudanese authorities arrested at least nine opposition leaders and activists, a group of civil society groups said on Friday.
The head of the media office at the National Intelligence and Security Service denied any knowledge of the arrests.
Sudan has been rocked by more than a week of anti-government protests sparked by rising prices, shortages of basic commodities and a cash crisis. At least 19 people have died during the protests, including two military personnel, according to official figures.
A committee of professional organizations involved in the protests said in a statement that authorities had raided a meeting of opposition leaders in Khartoum. They detained a total of nine people, including Siddiq Youssef, a senior leader of Sudan’s Communist Party, as well as leaders from the pan-Arab Baath and Nasserist parties, the statement said.
The raid came after a coalition of opposition groups called for more protests after the weekly noon prayers on Friday.
Fourteen leaders of one of Sudan’s two main opposition groupings were detained last Saturday and then released some nine hours later.