Egyptian anti-government groups on Thursday held a march in central Cairo in protest at a law that imposes strict limits on public demonstrations.
Three prominent activists were recently jailed for three years under the provisions of the law.
Thousands of protesters, both Islamists and non-Islamists have been arrested since the law was enacted last November.
The march, organised by the Way of the Revolution movement, started with a press conference at the Journalists Syndicate and a sit-in on the steps of the building, followed by a march in the streets close to Tahrir Square.
Protesters called for the release of those detained at previous illegal demonstrations.
Groups supporting the protest included the April 6 Youth Movement and the Revolutionary Socialists.
The government said the protest law, passed in November of last year, was essential to bring back control and stability to the streets.
Under the law, protest organisers are required to notify the authorities at least three day prior to any public demonstration. Violators can be punished with jail terms and hefty fines.
Several local and international rights groups have criticised the law and the way it has been used by authorities.
Earlier this week, an Egyptian court rejected an appeal by activists Ahmed Maher, Mohamed Adel and Ahmed Douma against their three-year prison sentences and fined each LE50,000 for protesting without permission.
At the protest on Thursday, demonstrators held banners with the slogans “release Egypt" and "release the prisoners of revolution" and held pictures of the jailed activists.
They also chanted against former military chief Abdel-Fattah El-Sisi, a presidential hopeful likely to have a sweeping victory at the upcoming presidential elections.
Leading member of Way of the Revolution movement, Zizo Abdo, told Ahram Online the group had agreed on a number of escalating events including student protests and protest graffiti.
He said a conference by legal representatives of different movements will be held Monday and another conference by rights groups including Hisham Mubarak Law Centre Saturday.
The two conferences will plan a framework to get the protest law suspended.
"This law is part of a legal repressive effort by the regime," Abdo said. "This regime does not want any kind of dissent even if it was patriotic and peaceful."
Demonstrations, particularly by supporters of ousted president Mohamed Morsi, did not stop the law was issued, but the size of anti-government street protests seem to have reduced.
"We are not against a law organising protests but this law suppresses demonstrations," Abdo said. "This is a real flaw of this interim regime."
On 26 April, the different groups will march to the presidential palace in Cairo to demand Interim President Adly Mansour suspend the law.