CAIRO >> A deadly suicide bomb attack outside a Christian church in Alexandria on Saturday has forced the government and religious leaders here to acknowledge that Egypt is increasingly plagued by a sectarian divide that could undermine the stability that has been a hallmark of President Hosni Mubarak’s nearly three decades in power.

As Egypt’s Christians headed to church under heavy security Thursday night to observe Coptic Christmas Eve, the nation was struggling to come to terms with a blast that killed at least 21 people, highlighted a list of public grievances with the government and prompted concerns that national cohesion was being threatened by the spread of religious extremism among Muslims and Christians.

“I have heard this a lot, that this type of incident might be the first in a series, turning Egypt into another Iraq — that is the fear now,” said Ibrahim Negm, the chief spokesman for Grand Mufti Ali Gomaa, the nation’s highest religious official. “There is a paradigm shift here that says we have to do something about the sectarian issue.”

The bombing, which the authorities said bore the characteristics of an operation by al-Qaida, has increased the likelihood that Mubarak, 82, who has had health problems, will seek a sixth six-year term this year, in order to preserve the status quo. Yet, it is precisely that stability — or, some say, stagnation — that many Egyptians now cite as perhaps the nation’s greatest underlying problem.

“The regime fooled us for many years with the illusion of ‘stability,”’ wrote Magdy el-Gallad, in the independent daily newspaper Al Masry Al Youm. “We neither progressed nor has our situation remained stable.”

After the bombing and the ensuing riots, political experts, politicians, commentators, opposition leaders and average citizens said that the very steps taken by the president in the name of stability — including preservation of an emergency law that allows arrest without charge — had produced a state with weak institutions, weak political parties and a bureaucracy unable to resolve the social, political and economic problems that helped cultivate extremism.

“It is very clear that the government totally lost control — of everything,” said Muhammad Aboulghar, a professor at Cairo University medical school and a liberal activist. “The only control they have is on the security of the president, the group around him, and few other party figures. That’s it.”

But for all the criticism it unleashed, the blast appears to have forged a consensus that Egypt, despite its tradition of moderate Islamic thinking and multicultural tolerance, has in recent years become overwhelmed by fundamentalist religious identification, a position that until now the government strongly denied.

That view has reinforced the growing belief that Mubarak was not ready to surrender the reins of power, people here said. Mubarak underwent surgery in Germany last year and appeared frail for months afterward, leading to speculation about who might succeed him. But people who have recently met with him said that he appears to have regained his strength and seems to have no intention of giving up power.

There is also a belief among those in the political elite, the military, the business community and the governing National Democratic Party that with so much uncertainty — even before the bombing — that this is not the time for the party to nominate Mubarak’s son, Gamal, to run in September’s presidential election.

“If Mubarak disappears tomorrow, you will have the Islamists as the strongest political force in the country,” said Mohammed Salmawy, head of the Arab Writers Union. “The political parties, even lumped together, do not have the power to take over, and you have the army, which will not allow the country to go into chaos. Worse yet, you might have military Islamic rule because there is no reason to suppose the army is any different than society.”

When the bomb exploded shortly after New Year’s Eve Mass, the government moved with unusual speed and certainty. Within hours, Mubarak made a nationally televised address calling for national unity. Muslim religious leaders, like Gomaa, quickly condemned the attack and reached out to the leader of the church, Pope Shenouda III.

Within days there were pop songs on the radio calling for national unity; billboards around the nation displaying the crescent moon and the cross, symbols of both faiths; and promises that government officials would this time follow through on plans to prevent more violence and correct the underlying problem.

But the effort was widely dismissed here as window dressing by an out-of-touch elite.

“While Egyptian officials fell in love with numbers — of streets paved, of hospitals built, the number of hotels and so on — somewhere the symbolic or the ideological mission of the state withered away,” said Ali Eddin Helal, a senior official in the National Democratic Party. “No state can live just by figures or by numbers. You have to give people meaning.”

The talk of unity failed to stop Christians and their supporters from pouring into the streets by the thousands.

“The government is corrupt,” shouted Mina Magdy, 23, who joined one of the demonstrations in the Shoubra neighborhood of Cairo on Tuesday. “If there was justice, nobody would dare do this. But the people who kill are not being held accountable.”

The bombing opened the floodgates of frustration among Christians who had long chafed under what they saw as discriminatory laws.

Many complained that the government had allowed unrestricted construction of mosques while restricting even the restoration of churches. They complained that no one had yet been tried in a Christmas Eve shooting  last year in Nag Hammadi, a town in Upper Egypt where a Muslim gunman fired on Christian worshipers, killing seven people and wounded 10. And they complained about the last parliamentary elections, in which the opposition emerged with fewer than 20 seats out of a total of 518 in Parliament, fueling accusations of fraud and vote rigging, which the government has denied.

“This sectarian atmosphere is driving young people to retreat and lock themselves within the framework of the church,” said Gamal Asaad, a Coptic Christian and member of Parliament. “There is no room for political participation, which makes them susceptible to the conservative religious discourse. If there were real elections, if there was real representation, if there was any real participation by the people, then the political decisions could be more appropriate and address all these problems.”

In the past few years, Egypt has struggled through a seemingly endless series of crises and setbacks. The sinking of a ferry left 1,000 mostly poor Egyptians lost at sea, an uncontrollable fire gutted the historic Parliament building, terrorists attacked Sinai resorts, labor strikes affected nearly every sector of the work force and sectarian-tinged violence erupted, including last year’s shooting in Upper Egypt.

And in nearly every case, the state addressed the issue as a security matter, deploying the police, detaining suspects, dispersing crowds. That was also true in 2010, even as evidence mounted of growing tension between Egypt’s Muslim majority and a Christian minority that includes about 10 percent of the approximately 80 million Egyptians.

“I think that 2010 was a very, very bad year in the history of Egypt,” said Mona Makram-Ebeid, a former member of Parliament from a prominent Christian family. “Will this be a national awakening? If not, it might portend very, very dangerous days to come.”

© 2011 The New York Times Company