CAIRO — A Cairo court on Saturday handed jail sentences to two dozen people and reaffirmed death sentences for 21 others convicted of involvement in a deadly soccer riot, in a case that has spurred weeks of violence and has driven public anger at Egypt’s police force to a dangerous high.

Seventy-four people, most of them fans of the Al-Ahly club team, died in the 2012 riot in the Suez Canal city of Port Said, after fans of the home Al-Masry club team stormed the pitch, setting off a stampede that police failed to control.

But the Saturday ruling on the remaining 52 of some 73 defendants charged in the case, most of them soccer fans, brought closure to very few in Egypt, where citizens say that police violence and a lack of government transparency in the two years since the fall of Hosni Mubarak have them rapidly losing faith in the nation’s new president, court system and police force.

Hundreds of soccer fans in Port Said took to the streets on Saturday after hearing the sentences, most of which affected residents of the city, and tried to disrupt ship traffic in Egypt’s vital Suez Canal, witnesses said.

In Cairo, fans of the Al-Ahly club team, who claim most of the soccer riot’s victims as their own, lashed out for sentences that they deemed too light, sparring with police in downtown Cairo and setting a police club and the country’s football federation headquarters on fire. Two persons were killed in the clashes in Cairo, state media reported.

For many, the anger was a foregone conclusion in a case that Port Said residents say has been marred by corruption and dirty politics.

“We feel a great injustice,” said Mohamed el-Sakka, a 21-year-old protester in Port Said. “We have learned that the judiciary can be very politicized, that things happen without us knowing, behind our backs. We have completely lost faith in the judiciary,” he said.

On Saturday, the court reaffirmed the death sentences of 21 Al-Masry fans, sending fresh waves of shock and anger rippling through Port Said, where the initial announcement of that ruling in January set off days of clashes between protesters and police that left dozens more dead.

But the court also acquitted 28 defendants, including seven of the nine police officers charged in the case, lending credence to a widely held perception that the police — once the enforcers of Mubarak’s authoritarian regime — continue to operate with impunity.

Thousands of police have withdrawn from their stations and camps across the country since Wednesday, in strikes over working conditions that they say have made them easy victims and scapegoats in clashes with protesters, and which deny them the appropriate weapons to defend themselves.

Rights groups and activists have accused police of using excessive force, including torture of detainees. Only a few of the dozens of police and security officials charged in violent incidents during and since Egypt’s 2011 uprising have gone to jail for the crime.

The protests and clashes have become nearly daily occurrences in Egypt over the past four months, rattling the Islamist-dominated government of President Mohammed Morsi, and raising the specter of further unrest to come.

In Port Said on Saturday, soccer fans and relatives of the victims broke down in tears, and convened angry marches, witnesses said. Some tried to disrupt ship traffic in the Suez Canal by unmooring boats and setting them adrift in the waterway, Reuters reported. Others set tires around the harbor on fire.

The Suez Canal is Egypt’s most strategic asset and its biggest source of revenue, a fact that has amplified the potential impact of wide-ranging violence along the canal zone, which has seen some of the worst violence between police and protesters during and since the revolution.