A riot policeman throws a tear gas canister which was thrown back by protesters opposing Egyptian President Mohamed Mursi during clashes along Qasr Al Nil bridge, which leads to Tahrir Square in Cairo March 9, 2013. [Photo/Agencies]

CAIRO - Egyptians took to the streets and set buildings on fire Saturday following a disputed court ruling on a deadly soccer riot last year.

The Port Said riot, which killed at least 70 people and injured hundreds of young soccer fans, took place on February 1, 2012, when assailants stormed into the field after a football game and attacked the audience.

The criminal court in Port Said reaffirmed death penalties for 21 convicts on Saturday, sending five to life imprisonment, ten, including two former top Port Said police officials, to 15 years in prison while others received shorter terms. It has acquitted 28 out of a total of 73 defendants.

Thousands of protestors from Utras Ahlawy, a group supporting the Egyptian premier league football club Al-Ahly, gathered outside Al-Ahly headquarters in Cairo and vowed to avenge their fellows killed in the riot.

Ramy Essam, a member of Ultras Ahlawy, said that the verdict was "dissatisfactor," and that "sentencing former Port Said security chief to 15 years in prison is not enough compared with the massacre."

Another Al-Ahly fan, Hesham Ahmed, said the verdict was "politicized".

"How come 21 civilians get death penalties while involved Port Said police chiefs and officers get years of prison or acquittance?" Ahmed said, describing the verdict as "unjust, ridiculous and tricky."

The mother of Anas, a young victim of the riot, said tearfully that her son never returned from the football match but she did not want the protestors to get into trouble.

"The verdict could have been stricter, but I am satisfied. We family members of the victims do not want to get our children of the ultras into trouble. We want things to cool down and life gets back to normal," she told Xinhua.

As furious young soccer fans left the streets chanting "the government should fear us," smoke arose around the Cairo Tower after a nearby police club building and the Egyptian Football Association (EFA) building were set on fire.

Eyewitnesses told Xinhua the attackers broke into the EFA, torched the building and looted cups, medals and documents before they fled.

"I do not think the attackers were from Ultras Ahlawy. They were a group of about 500 young men who threw stones and Molotov cocktails at the EFA building, then they broke into it, set it on fire and looted whatever they could," said an eyewitness Karim Hosni Mohamed.

In Port Said, meanwhile, protestors marched the streets with quite different reasons.

"It is a weird verdict," said Amr Samy, spokesman for Ultras Masrawy, a group leading peaceful marches around the city.

"It is the first time in Egypt to see 21 death penalties in one case. It was meant to placate Cairo at the expense of Port Said."

Samy argued that forensic reports said most deaths were out of suffocation and crowd pushing, not premeditated murders. He said the people of Port Said would peacefully appeal the verdict through legal means.

Despite the difference, Cairo and Port Said fans both blamed the Interior Ministry for sentencing some innocent civilians to death to cool down public opinion.

"We all reject this court verdict that oppressed some innocent young men. The verdict was shocking and the people of Port Said could hardly believe it," Al-Sayed al-Dawwy, 50, told Xinhua.

"We demand retaliation for Port Said victims. We will continue our civil disobedience and we will appeal the ruling against our defendants," his colleague Adel Hakim said.