A coalition of unions in Sudan says it plans to "paralyze" the government with the first of what it says will be indefinite strikes by professionals.
Doctors and other hospital workers plan to stay off the job Monday and only deal with emergencies.
The coalition urges all Sudanese to keep up their street protests against the government of President Omar Bashir, triggered last week by shortages of food and fuel and a sharp jump in the price of bread.
Police used tear gas against a group of demonstrators who emerged from a football stadium in Omdurman Sunday, chanting "freedom" and "the people want the fall of the regime."
Protesters in other cities blocked roads and burned tires.
The reported death toll since the protests erupted last Wednesday ranges from eight to 22.
Government officials blame the protests on what they call infiltrators and saboteurs.
A tweet sent out by the state-run news agency says the Sudanese military "stands behind its leadership" and will safeguard the country's security and safety and honor.
Bashir seized power in a 1989 Islamist-led coup that ousted democratically-elected Sadeq al-Mahdi, who is now Sudan’s opposition leader.
In the past, Bashir has shown little tolerance for dissent.