Protests erupted at universities across Egypt on Sunday, condemning a court decision to drop criminal charges against Hosni Mubarak, who was ousted in the 2011 uprising.
Hundreds of demonstrators gathered at Cairo University, waving pictures of Mubarak behind bars and demanding the "fall of the regime", the rallying cry of the Arab Spring uprisings that shook governments from Tunisia to the Gulf in 2011.
Police stood ready at the gates to bar students that sought to take their demonstration into the streets.
Two people were killed and nine were wounded on Saturday evening, when security forces fired tear gas and birdshot to disperse about 1,000 protesters who attempted to enter Tahrir Square - the symbolic heart of the revolt that ousted Mubarak.
Security forces closed a Cairo metro station, the state news agency said, an apparent effort to prevent gatherings downtown.
Clashes also erupted at Zagazig University in the Nile Delta, and the state-owned Al-Ahram newspaper said 11 students were detained after setting fire to a building.
Egypt’s interior ministry claimed in a statement on Saturday night that the protests were peaceful until 6PM when elements of the banned Muslim Brotherhood joined them, Ahram Online reported.
Brotherhood protesters chanted against the army and police and threw rocks at security forces, said the statement.
An Egyptian court on Saturday dropped its case against Mubarak over the killing of protesters in the 2011 uprising that ended his 30-year rule.
His supporters erupted in celebration when the verdicts of that retrial - which also cleared Mubarak's former interior minister, Habib al-Adly, and six aides - were read out. The defendants had denied the charges.
The court also cleared Mubarak and a former oil minister of graft charges related to gas exports to Israel.
In a separate corruption case, charges were dropped against Mubarak and his sons Alaa and Gamal, with Judge Mahmoud Kamel al-Rashidi saying too much time had elapsed since the alleged crime took place for the court to rule.
Mubarak denied all the charges in a phone call on Saturday shortly after the verdict.
“They then turned against us," Mubarak told private-owned satellite channel Sada al-Balad, saying that he could not say who he was referring to, the Aswat Masriya website reported.
Upon Mubarak’s return to the hospital after the trial, he was greeted with celebrations and salutes by a number of military officers, according to the a medical source at the Maadi Military Hospital.
"I knew that God would stand by me and grant me victory and that the truth will prevail during the trial session. I have not committed any crimes," said Mubarak, according to the report.
Regarding the sentence of three years Mubarak received for corruption; it is possible the ex-president could be released early after serving two-thirds of this period, his lawyer Farid al-Deeb told AFP on Sunday.
"Under a recent legal amendment, there can be a release once two-thirds of a sentence has been served," said Deeb.
The website of Egypt's Muslim Brotherhood Freedom and Justice party decried the acquittal on its website.
“A junta's judge has acquitted Mubarak and his criminal cronies who freely spilled the blood of the Egyptian people, insulted, humiliated and robbed Egyptians, and squandered the country's wealth,” said the statement signed by the Muslim Brotherhood on Saturday.
“With this acquittal, the junta judge has also ruled that the Egyptian people have no right to a free and dignified life, that Egyptians do not deserve to enjoy their own homeland's riches, and that they do not have the right to hold accountable those who commit crimes against the people.”
Many Egyptians who lived through the rule of former airforce officer Mubarak view it as a period of autocracy and crony capitalism.
His overthrow led to Egypt's first free election. But the winner, Mohamed Morsi, was ousted last year by the army, led by Abdel Fattah al-Sisi, after Morsi’s rule became more autocratic as he sought to seize power for the Muslim Brotherhood. Sisi won a presidential vote in May.
Egyptian authorities have since jailed Morsi and thousands of his Muslim Brotherhood supporters, sentencing hundreds to death in mass trials that drew international criticism.
By contrast, Mubarak-era figures have been released and new laws curtailing political freedoms have raised fears among activists that the old leadership is back.
"Down with Hosni Mubarak, down with every Mubarak, down with military rule" said one Facebook page that called for protests against the ruling.
The verdict has also prompted a deluge of online cartoons about the return of the old guard.
One animated video begins with a group of Mubarak-era politicians in a darkened cell facing an array of charges. One by one they are released and end up celebrating their freedom with their former president, singing "yes, we are back".