An Egyptian emergency court on Sunday began the trial of 48 Muslims and Christians charged with inciting deadly sectarian clashes in Cairo's Imbaba district in May.
A new dock was created in the courtroom in order to separate the Muslim and Christian defendants, as security forces surrounded the courthouse and families of the defendants staged protests outside.
The 28 defendants present — the search continues for 20 — all pleaded not guilty to charges ranging from premeditated murder and inciting sectarian tension to harming public security.
A security source said the case was adjourned until 4 September.
The clashes on 7 May in the working-class neighborhood of Imbaba, an overcrowded maze of residential buildings and shops, left 12 dead and 52 injured.
Muslims had attacked the Coptic Saint Mena church in Imbaba in a bid to free a Christian woman they alleged was being held against her will because she wanted to convert to Islam.
Copts scuffled with soldiers, blaming them for not doing enough to stop the fighting.
The clashes prompted hundreds Coptic Christians to hold a sit-in outside the state television headquarters to demand protection.
That sit-in was attacked a week later, sparking further clashes that left dozens injured, raising fears of widespread sectarian unrest.
Egypt has been gripped by insecurity and sectarian strife since a revolt that toppled president Hosni Mubarak on 11 February created a security vacuum.
After the clashes, the Supreme Council of the Armed Forces, which took power when Mubarak was ousted, warned it will "strike with an iron hand all those who seek to tamper with the nation's security."
Coptic Christians, who account for up to 10 percent of Egypt's 80-million people, complain of discrimination and have been the targets of several attacks.