Following a court verdict on Saturday, rioters set two public buildings in Cairo ablaze, plunging Egypt into more chaos and giving beleaguered president Mohamed Morsi a fresh challenge as he bids to control an outpouring of anger in several cities.
The visibly angry crowd, identified by eyewitnesses as members of Ultras Ahlawy, a group of ardent Ahly supporters, embarked on a rioting spree after seven security officials were acquitted in the infamous Port Said football disaster trial.
Three people have also died, one an eight-year-old, in separate clashes between protesters and police forces on Qars El-Nil Bridge near Tahrir Square, which has been a hotbed for demonstrations since the 2011 uprising that toppled autocratic leader Hosni Mubarak.
Two of the nine security officials charged in the Port Said case received 15-year prison sentences each, but the verdict was not enough to placate the anger of Ultras Ahlawy members who vowed to take the matter into their own hands; intending to make up for what they perceive as lenient punishments for the culprits of Egypt's worst-ever football disaster.
Former Port Said security director Essam Samak and the head of the city's water-bodies security department, Mohamed Saad, were convicted for their role in the deaths of over 70 Ahly fans, who were confronted by a hostile Masry crowd at the end of an ill-tempered league game on 1 February 2012.
"Today’s acquittals of most of the police 'dogs' are a clear sign that the trial was a sham and the officials we stressed should be convicted were intentionally found innocent," Ultras Ahlawy said in another strongly worded statement on their official Facebook page.
"What happened today in Cairo is only the beginning of our rage. Even more of it will surface if all officials involved in the massacre are not put on trial. We will not be placated by the sentencing of just two police 'dogs'."
The court also confirmed death penalties by hanging for 21 Masry fans and sentenced five more people to life imprisonment. The convictions did little, however, to appease the protestors who torched the Egyptian Football Association (EFA) premises and a police social club in the upscale Zamalek district, Cairo.
The EFA headquarter was also ransacked, with photos posted on social network sites showing men grasping the African Cup of Nations trophy, the precious prize Egypt's national team won three times in 2006, 2008 and 2010. The cup was later safeguarded by officials who were present at the scene, according to the Public Prosecution.
"Large numbers of Ultras Ahlawy burned all the documents and papers. The history of Egyptian football is now lost and cannot be recovered," said EFA chief executive Tharwat Sweilam.
The EFA opted against halting domestic football activity despite previous threats from Ultras Ahlawy that they would ruin any attempts to stage Premier League games "if justice was not done in the Port Said case".
Saturday's violent scenes in Cairo were in stark contrast to the jubilant celebrations of Ultras Ahlawy after the first court ruling in late January sentenced 21 Masry fans to death.
Since the verdict in January, Port Said has been bristling with anger, witnessing intermittent clashes with police leaving over 40 killed and prompting the army to intervene in an attempt to quell unrest. However, it was relatively calm on Saturday.
"We will focus on big acts of civil disobedience across Port Said, until our demands are fulfilled," Aly Spice, founder of Port Said's Green Eagles Ultras, told Ahram Online's Bel Trew.
"We want a retrial with a fair judge, justice for those killed in the recent clashes by security forces and the 21 defendants facing the death penalty not to be executed. We are being targeted because the address on our IDs is Port Said - it's tantamount to racism.
"It is all because President Mohamed Morsi and his government are bowing to pressure from the Ahly Ultras, as they are widespread across the country. We were persecuted for three decades under Mubarak, and Morsi is continuing this."
Some protesters briefly tried to disrupt international shipping on the Suez Canal but the path of passing vessels was not affected, according to Suez Canal Authority spokesman Tarek Hassanein.
Islamist President Morsi, who was propelled into power by the influential Muslim Brotherhood last year, is enduring a torrid time as he tries to revive a faltering economy and keep at bay an opposition angry at what they see as his attempts to monopolise power.
Sporadic clashes are ongoing in several cities and calls for civil disobedience are increasingly gathering momentum as protesters heap more pressure on Morsi, whose tenure is so far marred with violence and political turmoil.
The canal cities of Suez and Ismailia and the Nile Delta cities of Tanta, Mahalla and Mansoura have witnessed deadly clashes recently.
Cairo is also the scene of intermittent confrontations in downtown, where three people, including an eight-year-old child, died of birdshot wounds and tear gas inhalation near Qasr El-Nil bridge on Saturday.
"We should not give any political cover for violence or vandalism," Ayman Ali, an adviser to Morsi, told a news conference.
"We should not mix violence with political problems. However, the country needs political solutions to many things, including opening a dialogue with opposition."
Morsi's efforts to start parliamentary elections in April were scrapped by an Administrative Court ruling which said the electoral law must be reviewed by the High Constitutional Court, a process which is likely to delay the vote.
Apart from the legal wrangles, the president could still find it difficult to hold elections in cities that are increasingly hostile towards him.