Rioting sparked by death sentences passed on fans of a local football team has rocked Egypt's Port Said for a second straight day, leaving another six people dead and more than 460 injured.
Crowds attempted to storm three police stations in the canal city and others torched a social club belonging to the armed forces, looting items inside, security officials said.
The latest casualties, among the six a teenager shot in the chest, add to the toll of 31 people, including two anti-riot police killed on Saturday in the Mediterranean city.
Clashes also broke out in Cairo between police and protestors who accuse President Mohamed Morsi of betraying the goals of the revolution that ousted Hosni Mubarak two years ago, highlighting deep political divisions in the country now ruled by Islamists.
State television said Morsi would address the nation later in the day.
The rioting in Port Said began on Saturday after a Cairo court handed down death sentences on 21 supporters of the local football club, Al-Masry, after football violence last year that left 74 people dead.
Minutes after the sentences were passed, protestors attacked police stations and set tyres alight. Relatives of those sentenced to death clashed with security forces as they tried to storm the prison where they are being held.
Residents of the canal city carried out the grim task of burying those killed the previous day, with bodies wrapped in white shrouds being carried in open coffins by a sea of mourners along the city's main avenue.
'Our city is being hit by the interior ministry!' and 'Down with Brotherhood rule!' chanted the crowd, referring to the Muslim Brotherhood from which President Morsi draws his main support.
A brief burst of gunfire sent mourners running in several directions amid chaotic scenes, which later degenerated into rioting again.
In Cairo, angry anti-riot policemen barred Interior Minister, Mohammed Ibrahim, from attending the funeral of their two colleagues killed in the Port Said clashes on Saturday, the official news agency MENA reported.
The action was taken in protest at police not having been armed with live rounds to protect themselves, it said.
Clashes during the night in Cairo, near Tahrir Square - symbolic heart of the 2011 uprising that ousted President Mubarak - continued sporadically during the day and into Sunday evening, witnesses said.
Demonstrators briefly blocked the 6 October bridge, a vital link between east and west Cairo, as well as a metro line, they said.
Unrest also erupted on Sunday in Suez, another canal city, where protestors surrounded a police station, lobbed Molotov cocktails at security forces and blocked the road leading to the capital, security officials said.