Sudanese security forces fired tear gas and stun grenades on Friday at 300-400 chanting worshippers as they left a mosque near the capital, a Reuters witness said, after a call for widespread anti-government protests by opposition groups.
Activists had urged protesters to gather in large numbers following Friday's weekly Muslim prayers. Civil society groups said authorities arrested nine opposition figures on Thursday evening ahead of the planned demonstrations.
The group in Omdurman, a town near Khartoum, was fired upon as people exited the mosque chanting "peaceful, peaceful," the witness said. Around 30 SUVs belonging to the security forces had surrounded the square outside the building before noon prayers.
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. Amnesty International said on Tuesday at least 37 had died.
The head of the media office at the National Intelligence and Security Service denied knowledge of Thursday's arrests.
A committee of professional organisations involved in the protests said in a statement that authorities had raided a meeting of opposition leaders in Khartoum.
The nine people they had detained included Siddiq Youssef, a senior leader of Sudan's Communist Party, as well as leaders from the pan-Arab Ba'ath and Nasserist parties, the statement said.
Fourteen leaders of one of Sudan's two main opposition groupings were detained last Saturday and then released hours later.
Sudan has been gripped by a deep economic crisis that began in 2011 after the southern half of the country voted to secede, taking with it three-quarters of the country's oil output, and has been aggravated by years of overspending and mismanagement.
Opposition groups blame President Omar al-Bashir, who has governed Sudan since 1989, for the mismanagement. A series of measures, including a sharp devaluation of the Sudanese pound in October, have failed to shore up the economy.
In January, Sudan was shaken by demonstrations triggered by high bread prices.
But the protests that began on Dec. 19 appear to be more serious. Authorities have shuttered schools and declared curfews and states of emergency in several regions, and residents say police have used tear gas and sometimes live ammunition against demonstrators.
Putting the death toll at 19, Sudan's information minister on Thursday blamed some of the deaths on scuffles between shopowners and what he described as looters. He said 219 civilians and 187 members of the security forces had been wounded.
Journalists at the daily Al-Sudani said one of their colleagues was beaten by security forces after protesters passed next to the independent newspaper's offices.