Egyptian protesters are marching to mark one year since 27 demonstrators were killed in a Coptic Christian protest that was violently put down by security forces.
The Maspero Youth Union, a group of Coptic activists formed in the wake of October's deadly protest that left Egypt's Christian community deeply scarred, called for a march beginning at 4pm (14:00 GMT) in Cairo.
"The only political demand on this day is to seek justice for the martyrs and for the criminals implicated in the massacre be tried," the group said in a statement on Facebook.
Al Jazeera's Sherine Tadros, reporting from Cairo, said thousands of people were taking part.
"It feels like a funeral - very sad. People [are] holding up banners demanding Mohammed Tantawi [headed Supreme Council of the Armed Froces], Sami Annan [army chief of staff] and other ex-top brass to be held to account for the 27 deaths," she said.
The route followed by the marchers is from Shobra, a Cairo neighbourhood where many Copts live, to Maspero, our correspondent reported citing state television.
On October 9, 2011, thousands of demonstrators marched from Shobra to Maspero in central Cairo to denounce the burning of a church in the southern province of Aswan.
The protest was attacked and violence erupted when the army and riot police charged at the protesters leaving 27 Coptic Christians, one Muslim man and one policeman dead, according to Amnesty International, the UK-based rights watchdog.
Lethal force used
Graphic videos that were subsequently posted on the internet showed army vehicles driving into protesters at high speed.
In a report published last week, Amnesty International said that "armed and security forces used excessive, including lethal, force against those not posing a threat to them or others".
"The Egyptian authorities have failed to conduct a full impartial and independent investigation into the circumstances of the violence and to bring those responsible to account," the rights watchdog said.
That charge was followed by criticism of the Egyptian authorities by a local rights group that they had failed to bring to account those responsible for the deaths of Coptic Christians.
The Egyptian Initiative for Personal Rights says a "flimsy sentence" against three soldiers for the deaths of 15 of the protesters doesn't bring to account those ultimately responsible for the violence.
Hani Ramsis, lawyer, says a complaint against some of the generals who were ruling Egypt at the time was filed to the civilian prosecutor on Monday.
Egypt's Christians, who make up six to 10 per cent of the country's population of 83 million, have regularly complained of discrimination and marginalisation.
They have also been the target of numerous sectarian attacks.