A march against sectarianism will take place in Cairo on Tuesday afternoon.
Protesters will leave Fath Mosque in Abbasiya at 5pm and march to Saint Mark's Coptic Orthodox Cathedral.
Two people were killed and at least 90 injured when unknown assailants attacked mourners outside the cathedral on Sunday. A funeral had taken place for four Copts killed in sectarian violence in Qalioubiya, north of Cairo, on Saturday.
Police fired teargas over the walls of the cathedral compound and appeared to stand by as unknown assailants attacked mourners with birdshot, knives and petrol bombs.
In a statement, political groups and parties accused the Ministry of Interior of deliberately failing to protect the mourners and demanded the dismissal of the interior minister. They also called for the interior minister and the heads of Cairo and Qalioubiya security directorates to be put on trial for their deliberate failures to stop recent sectarian violence.
They also blamed the growing number of sectarian attacks on the government.
President Mohamed Morsi is to blame because "he lost legitimacy from the moment the first person was killed under his rule," the statement said.
Those calling for the march include the Constitution Party, the Egyptian Social Democratic Party, the Socialist Popular Alliance Party, the Free Egyptians Party, the Egyptian Current, the Free Egypt Party, the National Association for Change, the Egyptian Centre for Human Rights, Justice and Freedom Youth, the Revolutionary Socialists, and the Maspero Youth Coalition.