By Edmund Blair and Shaimaa Fayed
CAIRO, Jan 28 (Reuters) - A man was shot dead on Monday in a fifth day of violence in Egypt that has killed 50 people and prompted the Islamist president to declare a state of emergency in an attempt to end a wave of unrest sweeping the Arab world's biggest nation.
Emergency rule announced by President Mohamed Morsi on Sunday covers the cities of Port Said, Ismailia and Suez. The army has already been deployed in two of those cities and cabinet approved a measure to let soldiers arrest civilians.
A cabinet source told Reuters any trials would be before civilian courts, but the step is likely to anger protesters who accuse Morsi of using high-handed security tactics of the kind they fought against to oust President Hosni Mubarak.
Egypt's politics have become deeply polarised since those heady days two years ago, when protesters were making most of the running in the Arab Spring revolutions that sent shockwaves through the region and Islamists and liberals lined up together.
Although Islamists have won parliamentary and presidential elections, the disparate opposition has since united against Morsi. Late last year he moved to expand his powers and push a constitution with Islamist leanings through a referendum, punctuated by violent street protests.
Morsi's call for a national dialogue meeting on Monday to help end the crisis was spurned by his main opponents.
They accuse Morsi of hijacking the revolution, listening only to his Islamist allies and breaking a promise to be a president for all Egyptians. Islamists say their rivals want to overthrow by undemocratic means Egypt's first freely elected leader.
Anti-Morsi protesters were out on the streets again in Cairo and elsewhere on Monday, the second anniversary of one of the bloodiest days in the revolution that erupted on Jan. 25, 2011, and ended Mubarak's iron rule 18 days later.
Hundreds of demonstrators in Port Said, Ismailia and Suez, cities which all lie on the economically vital Suez Canal, had turned out against Morsi's decision on Sunday within moments of him speaking. Activists there pledged to defy a curfew that starts at 9 p.m. (1700 GMT).
Instability in Egypt has raised concerns in Western capitals, where officials worry about the direction of a key regional player that has a peace deal with Israel.
The political unrest has been exacerbated by street violence linked to death penalties imposed on soccer supporters convicted of involvement in stadium rioting a year ago.
In Cairo on Monday, police fired volleys of teargas at stone-throwing protesters near Tahrir Square, cauldron of the anti-Mubarak uprising. A 46-year-old bystander was killed by a gunshot, a security source said. It was not clear who opened fire.
"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.
Propelled to the presidency in a June election by the Muslim Brotherhood, Morsi has lurched through a series of political crises and violent demonstrations, complicating his task of shoring up the economy and of preparing for a parliamentary election to cement the new democracy in a few months.
"The protection of the nation is the responsibility of everyone. We will confront any threat to its security with force and firmness within the remit of the law," Morsi said, angering many of his opponents when he wagged his finger at the camera.
The president offered condolences to families of victims of violence and also called a dialogue meeting on Monday at 6 p.m. (1600 GMT) between Islamist allies and their liberal, leftist and other opponents to discuss the crisis.
The main opposition National Salvation Front coalition rejected the offer as "cosmetic and not substantive" and set several conditions that have not been met in the past, such as forming a national salvation government. They also demanded that Morsi announce his responsibility for the bloodshed.
"We will send a message to the Egyptian people and the president of the republic about what we think are the essentials for dialogue. If he agrees to them, we are ready for dialogue," opposition politician Mohamed ElBaradei told a news conference.
The opposition Front has distanced itself from the latest flare-ups but said Morsi should have acted far sooner to impose security measures that would have ended the violence.
"Of course we feel the president is missing the real problem on the ground, which is his own policies," Front spokesman Khaled Dawoud said after Morsi made his declaration.
Other activists said Morsi's measures to try to impose control on the turbulent streets could backfire.
"Martial law, state of emergency and army arrests of civilians are not a solution to the crisis," Ahmed Maher of the April 6 movement that helped galvanise the 2011 uprising said. "All this will do is further provoke the youth. The solution has to be a political one that addresses the roots of the problem."
Thousands of mourners joined funerals in Port Said for the latest victims in the Mediterranean port city. Seven people were killed there on Sunday when residents joined marches to bury 33 others who had been killed a day earlier, most by gunshot wounds in a city where arms are rife.
Protests erupted there on Saturday after a court sentenced to death several people from the city for their role in deadly soccer violence last year, a verdict residents saw as unfair. The anger swiftly turned against Morsi and his government.
Rights activists said Morsi's declaration was a backward step for Egypt, which was under emergency law for Mubarak's entire 30-year rule. His police used the sweeping arrest provisions to muzzle dissent and round up opponents, including members of the Brotherhood and even Morsi himself.
Heba Morayef of Human Rights Watch in Cairo said the police, still hated by many Egyptians for their heavy-handed tactics under Mubarak, would once again have the right to arrest people "purely because they look suspicious", undermining efforts to create a more efficient and respected police force.
"It is a classic knee-jerk reaction to think the emergency law will help bring security," she said. "It gives so much discretion to the Ministry of Interior that it ends up causing more abuse, which in turn causes more anger." (Additional reporting by Yasmine Saleh in Cairo and Yusri Mohamed in Ismailia; Editing by Giles Elgood and Peter Millership)