Critics on Sunday accused Egypt's courts of taking sides after the dropping of a murder charge against ex-president Hosni Mubarak, with experts and activists saying the country's hopes for democracy were being dashed.

A Cairo court on Saturday dismissed the charge against 86-year-old Mubarak over the deaths of protesters during Egypt's 2011 Arab Spring uprising.

Mubarak, who ruled Egypt for three decades until being driven from office, remains imprisoned in a military hospital in a separate graft case, but his lawyer Farid al-Deeb told AFP he could see early release after serving two-thirds of a three-year sentence.

The ruling came amid a crackdown by President Abdel Fattah al-Sisi and prompted claims the former military chief was abusing the justice system to fight political battles and reinforce his authority.

"The verdict further reinforces concerns about the alarmingly selective justice system in Egypt, which appears more intent on settling political scores and punishing dissent than establishing justice," said the Egyptian Initiative for Personal Rights (EIPR), a leading rights group.

Sisi, who led the overthrow of the elected Islamist president Mohamed Morsi in July 2013, has been accused of instituting a regime even more authoritarian than Mubarak's -- stifling dissent and counting on the support of a public exhausted by years of instability.

Experts said he has increasingly bent the courts to his aims, with hundreds jailed in mass trials that the United Nations has described as "unprecedented in recent history".

People are tired

In the latest case a court on Wednesday sentenced 78 teenage boys to between two and five years in prison for joining the blacklisted Muslim Brotherhood's rallies demanding Morsi's return.

"All of this proves that the justice system is in need of reform," human rights lawyer Gamal Eid said.

Since the army ousted Morsi in July 2013, the government has launched a bloody crackdown against his supporters, leaving at least 1,400 dead and more than 15,000 jailed.

For Paris-based Middle East expert Karim Bitar, the Mubarak ruling was a "judicial farce" that shows the regime "is not even bothering to worry about appearances".

The ruling enraged Mubarak's opponents, with about 1,000 people taking to a central Cairo square to denounce the government.

Police used tear gas to disperse the protesters, prompting clashes that left two people dead and 14 wounded.

But the decision was largely greeted with indifference in Egypt, where only a few years ago hundreds of thousands rallied daily to demand Mubarak step down.

"After three years of instability and unrest, people are tired, the subject (of Mubarak's verdict) doesn't worry them, what they want is the stability that the current regime can offer," said Ashraf el-Sherif, a political analyst at the American University in Cairo.

For some critics, the ruling has cemented suspicions that Sisi, Mubarak's former army intelligence chief, is a direct descendant of the former regime.

"This verdict confirms that Mr Sisi is part of Mr Mubarak's regime," said Amr Ali, a leader of the April 6 movement that spearheaded the 2011 revolution but was earlier this year banned by the government.

Secular and leftwing activists have not been spared in Sisi's crackdown, with dozens jailed for violating a contentious law limiting the right to protest.

Ali said that for activists like himself, the message from the ruling was clear: "Your dream is over and there is nothing you can do about it because the tanks are everywhere and the military controls the country."