CAIRO (REUTERS) - Egyptian President Mohamed Mursi declared a month-long state of emergency in three cities on the Suez Canal, where dozens of people have been killed in protests that have swept the nation and deepened a political crisis facing the Islamist leader.

Hundreds of demonstrators in Port Said, Suez and Ismailia turned out against the decision within moments of Mr Mursi's announcement late on Sunday, which came after the death toll from protests and violence that erupted last week hit 49.

Mr Mursi also called for a national dialogue with his rivals for later on Monday, but the early response from members of the main opposition coalition suggested they saw little point, saying the president only seemed to listen to his allies.

Most deaths have been in Port Said, where 40 were killed in just two days. Riots were sparked on Saturday when a court sentenced to death several people from the city on charges related to deadly rioting at a soccer match last year. Mourners at Sunday's funerals in the port, where guns are common, directed their anger at Mr Mursi.

Violence in Egypt's cities has extended to a fifth day.

Police fired volleys of teargas at dozens of youths hurling stones on Monday near Cairo's Tahrir Square, where opponents have camped for weeks to protest against Mr Mursi, who they say betrayed the revolution that ousted Hosni Mubarak two years ago.

"We want to bring down the regime and end the state that is run by the Muslim Brotherhood," said Ibrahim Eissa, a 26-year-old cook, protecting his face from teargas wafting towards him from police lines near Tahrir, the cauldron of the 2011 revolt.

Propelled to power in a June election by the Brotherhood, Mr Mursi's presidency has lurched through a series of political crises and violent demonstrations, compounding his task of shoring up a teetering economy and preparing for a parliamentary election to cement the new democracy in a few months.