(Egyptians carry the coffin of a Shi’ite victim, who was killed in sectarian violence, before funeral prayers in El Sayeda Nafisa Mosque in Cairo, June 24, 2013. REUTERS/Amr Abdallah Dalsh)

Egypt’s president, accused of fuelling sectarian hatred, promised swift justice on Monday for a deadly attack on minority Shi’ites as he tried to quell broader factional conflict to avoid a threatened military intervention.

The army, which handed power to elected Sunni Islamists a year ago after decades of oppression, have warned Mohamed Mursi – and his liberal opponents – to end an increasingly violent deadlock or see troops back on the streets to impose order.

There was little sign of reconciliation, however. Liberals and Shi’ites accused Mursi, who announced he will address the nation on Wednesday evening, of fostering sectarian hatred by associating with radical Sunni preachers.

As the army was speaking out on Sunday, a reminder of the fragility of the polarized new order that has emerged from the revolution of 2011, a mob in a Cairo suburb was raiding a house where Shi’ites were marking a religious festival, killing four and dragging bodies through the streets to cries of “Infidels!”.