Egypt's banned Islamist group the Muslim Brotherhood and Zamalek's hard-core fan group the White Knights were behind the football disaster that killed 20 fans, as part of a scheme to blight this month's economic conference in Sharm El-Sheikh, said the general prosecution on Tuesday.
The defendants are charged with acts of thuggery related to intentional murder, destruction of buildings and public properties, resisting authorities, and possession of explosive materials.
The prosecution has referred 16 people from both groups to a criminal court, ordering the arrest of four defendants who are still at large.
The casualties died last February in a stampede a few hours before Zamalek played ENPPI in a Egyptian Premier League game, as police used tear gas to disperse fans in front of Cairo's Air Defence Stadium. The country's top football competition has been halted ever since.
The prosecution said it was the Muslim Brotherhood group, from which ousted Islamist president Mohamed Morsi hails, who planned the chaos by paying money to members of the White Knights and giving them "explosive materials" to stir violence and mayhem.
"The prosecution's investigation proved that the terrorist Muslim Brotherhood, as part of its endeavor to bring down the pillars of stability of the country, used its relationship with cadres from the Zamalek club's fan group, the White Knights [to instigate the incident]," the statement reads.
The Brotherhood aimed at spreading fear and sabotaging the recently-held economic conference, added the statement, which also includes information on the two cases of killed activists Shaimaa El-Sabbagh and Mohamed El-Gendy.
"Some of the suspects who belong to the Muslim Brotherhood have confessed to planning, funding and participating in these crimes to create a state of security destabilisation and ruin the economic summit."
Commenting on the charges pressed against Brotherhood and Ultras members, lawyer Tarek El-Awady, who represents families of the victims, took a swipe at the prosecution.
"If someone looked at the sun and told you it's a kerosene lamp, how are you going to argue with him?" he said sarcastically.
"We filed a report with the prosecution against Zamalek president Mortada Mansour and [then] interior minister [Mohamed Ibrahim], and these reports were completely ignored. The prosecution has been adamant to keep investigations going in one direction," he added.
Ibrahim, who was replaced in a cabinet reshuffle earlier this month, came under fire for the police's conduct before the match.
Lawyer Mansour, meanwhile, also faced a wave of criticism for describing the fans involved in the incident as "thugs" who tried to attend the game without tickets.
Following a crowd ban since the infamous Port Said football disaster that left over 70 dead in February 2012, only 10,000 supporters were allowed to attend the match, with 5,000 tickets up for public sale and as many distributed by the club itself.
A lack of tickets is believed to have caused swathes of fans, on top of the allowed number, to try to enter, before the police fired tear gas at them.
A barbed wired cage near the entrance made it hard for the fans to escape.
"What happened was very clear to everyone, yet the prosecution insisted on repeating the security apparatus' argument. As I have said many times, blaming every single crime on the Brotherhood has put the prosecution's credibility at stake," El-Awadi concluded.
Egypt declared the Muslim Brotherhood to be a terrorist group in late 2013, a few months after Morsi was toppled following mass protests against his rule across the nation.
The country was hit by a series of bombings following the demise of Morsi's regime, with authorities leading a sustained crackdown on the Brotherhood and its Islamist allies, who have faced a myriad of charges over the past year and a half.
Meanwhile, the Ultras White Knights, like other Ultras groups in Egypt, have been at loggerheads with the police over the past years.
Apart from football-related clashes, members from the hard-core fan groups were instrumental in facing police forces during the 2011 uprising that toppled longstanding autocrat Hosni Mubarak, which is believed to have taken tensions between both sides to new heights.
Right after the February incident, the deadliest football-related one since the Port Said disaster three years ago, the Egyptian interior ministry said that clashes had occurred after Ultras White Knights members tried to attend the game without buying tickets.
Ultras White Knights disputed the ministry's account, saying they were tear-gassed as many fans scrambled to enter the stadium, with a "tiny metal fence surrounded by barbed wire being the only gate opened for us."