CAIRO, Egypt -- Egypt's main opposition coalition on Monday rejected the Islamist president's call for dialogue unless their conditions are met, a move that is likely to prolong the country's latest political crisis as violence that has left more than 50 people dead continued for a fifth day.

In the latest clashes, riot police fired tear gas at rock-throwing protesters in central Cairo on Monday, and one protester died of gunshot wounds, health and security officials said.

The violence came a day after President Mohammed Morsi vowed a tough response to the eruption of political violence, calling a state of emergency and curfew in the hardest hit areas -- three cities along the Suez Canal and their surrounding provinces. The military has deployed in two of those cities, Port Said and Suez.

The opposition has painted the explosion of rioting as a backlash against attempts by Morsi and the Muslim Brotherhood to monopolize power in Egypt -- and proof that Morsi has been incapable of achieving stability or achieving reforms.

Leaders of the main opposition coalition, the National Salvation Front, dismissed Morsi's invitation to a dialogue on resolving the crisis. At a press conference, the front's head Mohamed ElBaradei said the call was "without form and content."

ElBaradei said Morsi must first appoint a national unity government and name a commission to amend the disputed constitution that was ratified in a referendum last month before they can join a dialogue. He also wants Morsi to take legislative powers from the Islamist-dominated upper house of parliament, or the Shura Council, a usually toothless body elected early last year by less than 10 per cent of Egypt's registered voters.

"We support any dialogue if it has a clear agenda that can shepherd the nation to the shores of safety," said ElBaradei, flanked by former Arab league chief Amr Moussa and leftist Hamdeen Sabahi.

Sabahi, who finished a close third in last year's presidential election, added conditions of his own. Morsi, he said, must state publicly his political responsibility for the violence that engulfed the country since Friday, his respect for peaceful protests and fire the attorney general he named late last year.

The violence erupted around Friday's two-year anniversary of the start of the uprising that toppled autocrat Hosni Mubarak. Protests that turned to clashes around the country on Friday left 11 dead, most of them in Suez.

The next day, riots exploded in Port Said after a court convicted and sentenced to death 21 defendants for a mass soccer riot in the city's main stadium a year ago. During the weekend, 44 people were killed in violence in the city.

Throughout the past five days, anger over Morsi's policies and the slow rate of change have helped fuel the protests and clashes.

Angry and at times screaming and wagging his finger, Morsi went on national TV Sunday night and declared a 30-day state of emergency in the provinces of Port Said, Ismailiya and Suez, which are named after their main cities. A nighttime curfew goes into effect in those areas Monday.

Morsi has struggled to address the country's daunting social and economic problems since taking power in June, and his state of emergency call sparked criticism from opponents who accused him of using the same methods as Mubarak.

A relative unknown until his Muslim Brotherhood nominated him to run for president last year, Morsi is widely criticized and ruthlessly ridiculed in the media for having offered no vision for the country's future after nearly 30 years of dictatorship under Mubarak and no coherent policy to tackle seemingly endless problems, from a free falling economy and deeply entrenched social injustices to surging crime and chaos on the streets.

The rejection of his offer for a dialogue is likely to lend more weight to ElBaradei and his colleagues in the Salvation Front at a time when protesters on the streets are increasingly showing their independence from politicians, voicing a wide range of non-political grievances.