Video clips posted online show the fans in the stadium chanting “the people want to bring down the regime,” one of the main slogans of the Arab Spring uprisings.
Activists say police used tear gas and rubber bullets to disperse the fans after the match.
The violence late on Sunday was the latest in a series of anti-government protests across Sudan that have killed at least 12 people.
The protests were initially sparked by rising prices and shortages but soon turned to demands for al-Bashir, in power since 1989, to step down.
“Fuel and bread shortages may have triggered protests across the country, but other factors now seem to be helping to keep them going,” Al Jazeera’s Hiba Morgan, reporting from the capital, Khartoum, said.
“People seem to be frustrated not just by the economic crisis, but by the way the country is being run and they want to see change.”
Sudan’s doctors, meanwhile, began an indefinite strike on Monday, with organisers reporting a widespread response.
‘Officers join protesters’
On Sunday, the Sudanese military reiterated its support for al-Bashir in a statement, saying “The armed forces assert that it stands behind its leadership and its keen interest in safeguarding the people’s achievements and the nation’s security, safety along with its blood, honour and assets”.
Cited by the official SUNA news agency, the statement came amid reports that some senior military officers had joined protesters in the cities of Atbara, Gadarif and Port Sudan.
While official estimates put the death toll from the protests at 12, opposition groups say that at least 22 people have been killed in the unrest.
On Sunday, protests broke out in Omdurman, the twin city of Khartoum, and the North and South Kordofan states.
Sudanese authorities have announced a state of emergency and curfew in a number of provinces over the protests, with government officials accusing Israel of plotting with rebel groups to cause violence in the country.
A nation of 40 million people, Sudan has struggled to recover from the loss of three-quarters of its oil output – its main source of foreign currency – when South Sudan seceded.
Sudan’s economic woes have therefore exacerbated in the past few years, even as the United States lifted its 20-year-old trade sanctions on the country in October 2017.
The US has kept Sudan on its list of state sponsors of terrorism, which prevents Khartoum from accessing much-needed financial aid from institutions such as the IMF and the World Bank.
Bread prices have more than tripled since the start of this year after a government decision to stop state-funded imports of wheat.
Officials had hoped the move would create competition between private companies importing wheat, and therefore, act as a check on price rises.
But a number of bakeries stopped production, citing a lack of flour. This forced the government to increase flour subsidies by 40 percent in November.
Al Jazeera and news agencies