Political groups and parties are up-in-arms over the forced dispersal of two demonstrations in Cairo's downtown on Tuesday, calling for further protests Wednesday to demand the release of detainees.
Late Tuesday, three liberal parties issued a statement condemning the law and demanding the immediate release of all those detained in the protests.
"Passing the law in this form and at this time is an attempt by some currents within the government to return to repressive state security measures," the statement signed by the Popular Current, Egyptian Social Democratic Party and Free Egypt Party said. "The reality on the ground exceeded the illusions [of the state]."
The Doustor Party, a leading liberal group founded by prominent reformist Mohammed ElBaradie, warned the government that it needs "to expand its popular support, especially before a referendum on constitutional amendments,"
Their statement, issued late Tuesday night, maintains the new law "aims to deprive Egyptians of one of the most important achievements of January 25 revolution, after decades of denial of the right to peaceful protest."
Al-Doustor condemned the "excessive violence" and "random detention" of protesters, who it maintains were totally peaceful and keen not to block roads or assault security forces.
At least 50 protesters were arrested during Tuesday's protests, as the new law was implemented.
A copy of the prosecution report, obtained by Ahram Online, detailed the charges against 24 of those detained, including: rioting, organising a protest without notifying authorities, carrying white weapons, disrupting public interest, exposing people to danger, blocking roads, assaulting an employee during work, theft and thuggery.
The prosecution added that protesters had attacked one of the police officers, beat him and took his wireless device.
Detainees will remain in custody pending investigations.
The arrests came when two protests were defiantly staged in central Cairo; one to commemorate the death of a young man "Jika" killed by security forces last year, and the other to denounce military trials for civilians, a controversial article in the constitution about to be released.
Security forces asked protesters to leave within minutes, as they did not notify the Ministry of Interior of the protest, as per the new law. When they refused, police used water cannons and tear gas to forcibly disperse them.
Videos circulating on social media websites and local TV stations showed harsh treatment from the police, who dragged protesters and assaulted them.
The group of supporters of Gaber "Jika" Salah, who initially held the first protest Tuesday, as well as members of the 'Way of the Revolution Front', an anti-military anti-Brotherhood independent coalition, called for another demonstration Wednesday evening to demand the release of those detained and challenge the legitimacy of the protest law.
"Issuing a dicey law to close mouths is not a beneficial move in a country which has undergone a heated revolution for three years," Ahmed El-Hashemy, the spokesman for the Jika movement told Al-Ahram's Arabic news website. "A government that came to power amid protests cannot issue a law to prohibit them," he added.
A final version of the protest law was issued Sunday after being approved by interim President Adly Mansour. Controversial articles include requirements on protest organisers to notify authorities three days in advance of their aims and demands, heavy jail terms and fines for individuals who break the law, as well as escalating measures that security forces can deploy in dispersing protests.
A Muslim Brotherhood-led coalition, the National Alliance to Support Legitimacy, also issued a statement in condemnation of Tuesday's events, saying "these are repeated scenes against the supporters of legitimacy."
Muslim Brotherhood supporters have held near-daily protests since Islamist president Mohammed Morsi was ousted by the military in July. Demonstrations have often descended into bloody clashes with opponents or security forces, a pretext used by the government for issuing the new protest law.
A similar law was advocated during the one-year-rule of Morsi, who is currently on trial for inciting his supporters to kill their opponents in clashes in front of the presidential palace late last year.