A protest on Saturday in Cairo against a controversial law regulating demonstrations was dispersed after groups of people threw rocks and glass bottles at the protesters.
Police forces subsequently deployed teargas to disperse the crowds.
According to Freedom for the Brave, a campaign calling for the freedom of political prisoners, a number of protesters were arrested, including Sana Seif, sister of jailed blogger Alaa Abdel-Fattah, and a number of other protesters.
Rights campaigner Aida Seif El-Dawla wrote on her official Twitter account that three journalists had been arrested, including one from Al-Shorouk daily and another from Al-Watan.
Al-Shorouk daily confirmed its journalist Samer Omar was among those arrested in addition to a photographer from Al-Badeel news website.
Dozens of demonstrators were rallying against a law that requires all public demonstrations seek prior authorisation from the authorities. The protesters marched from Al-Haram metro station in Heliopolis in the direction of Itihadiya presidential palace in the same district of the city. Police cars had blocked off Khalifa El-Maamoun Street.
Liberal politician Gameela Ismail criticised the dispersal using her official Twitter account, saying that the Egyptian police had “reproduced what led to its fall” in the 2011 uprising, namely “attacks from criminals backed by police/teargas against peaceful protesters.”
The protest law was issued last November; it bans any protests that have not obtained a permit from authorities in advance.
The law was widely condemned by political activists, and a number have been arrested and convicted to jail terms under its provisions. Those serving sentences include prominent campaigners Ahmed Maher and Mohamed Adel of the April 6 Youth Movement, Ahmed Doma of the Egyptian Popular Current, Mahinour El-Masry of the Revolutionary Socialists and leftist blogger Abdel-Fattah.
Hundreds of Islamists have also been imprisoned on charges of violating the new law.
Solidarity protests were also planned in Athens, London, Paris, Berlin, Dublin and New York.