CAIRO — Violence erupted across the country Friday as Egyptians marked the second anniversary of their revolution with an outpouring of rage against the power of the Muslim Brotherhood.
At least seven people were killed in the canal city of Suez, state news media reported. More than 250 people were injured as protesters clashed with security forces around government facilities across the country, including the Interior Ministry headquarters, the state television building and the presidential palace in Cairo. And unidentified assailants attacked Muslim Brotherhood offices in several cities, including Cairo, the Delta town of Demanhour, and the canal town of Ismailia, where the group was founded 85 years ago.
The chaos was the clearest demonstration yet of the chasm of animosity and distrust dividing the Brotherhood and its opponents.
Although the Islamists of the Brotherhood have dominated elections since the ouster of the longtime president, Hosni Mubarak, two years ago, another broad segment of the population harbors deep suspicions of the group’s conservative ideology, hierarchical structure and insular ethos. Those doubts were redoubled last month when President Mohammed Morsi, with the Brotherhood’s political party, temporarily overruled the authority of the judiciary to ensure that his allies could push through an Islamist-backed constitution to a referendum despite the objection of other parties and the Coptic Christian Church.
It was also the latest confirmation that the Brotherhood had inherited not only Mubarak’s presidential palace but also the blame for Egypt’s myriad problems.
On Friday, five months after Morsi took power from Egypt’s interim military rulers, the demonstrators’ main complaint was that the Islamists had failed to fulfill the social welfare and social justice demands of the original uprising. A banner in the center of the square called for the repeal of the Islamist-backed constitution, passed in a referendum last month, which opponents say failed to enshrine ironclad guarantees of individual freedoms.
''The Egyptian people had so many dreams and the reality on the ground is, everything is still the same,’’ said Mohamed Adl, 41, a teacher who carried a sign with a handwritten poem accusing the Brotherhood of making ‘‘injustice the guard of our lives.’’
Protesters at times seemed to be re-enacting scenes from the 18-day revolt in 2011 that toppled Mubarak. The loudest chants were recycled from the revolution — ‘‘Leave, leave’’ and ‘‘The people want the fall of the regime.’’ Others were adapted slightly to focus on the Islamist Brotherhood, calling for an end to ‘‘the rule by the supreme guide,’’ Mohamed Badie, the Brotherhood’s spiritual leader.
By early afternoon in Cairo, a few dozen protesters at one corner of the square — many of them apparently teenagers — had begun to throw rocks over a cement barrier at security forces massed around the Interior Ministry building, resuming an intermittent battle that had begun the day before in anticipation of the anniversary. The security officers, as they typically do, threw back some of the rocks, and plumes of tear gas sailed overhead past a church steeple up the street.
State news media reported at around 3 p.m. that four people had been injured in the clashes with security forces near the square, in addition to 25 injured since the battle began the day before.
Osama Amir, 22, a student walking from the fight, said he did not know how it started or why.
‘'People have lost confidence in the central security forces, so when there is a chance to beat them up, we will beat them up,’’ he said.
A little while later, another fight broke out when demonstrators passed the office of the Muslim Brotherhood website on their way to the square and threw rocks at it. Other civilians — it was unclear whether they were annoyed neighbors or Brotherhood supporters — rushed out to strike back at the protesters, and a street vendor’s kiosk was burned in the melee.
Simultaneously, a group of masked men broke into the building and ransacked the Brotherhood office, overturning furniture, destroying computers and breaking glass. Neighbors of the building said the attack appeared to have been planned because the men had brought acid to break through a padlock.
The Brotherhood, hoping to avoid the kind of factional clashes that killed 10 people in December, had urged its supporters to stay away from the square and observe the anniversary with community service projects around the country.
Both the Brotherhood and its opponents are looking ahead to parliamentary elections expected to be held in April, and critics of the Brotherhood contended that its community service drive was in part an effort to curry favor with needy voters. The opposition had poured most of its energy into Friday’s demonstrations, and its critics said it was once again wasting its time on street protests while the Islamists had already turned their attention to the more important electoral battle.
''It is important that people go down to the square, if for no other reason than to remind Egypt, and themselves, that something really special happened during those 18 days two years ago,’’ said H.A. Hellyer, a researcher based here with the Brookings Institution. ‘‘That energy, however, can’t stay in the square,’’ he said. ‘‘It’s got to be channeled.’’
But some demonstrators argued that the public protests were a first step toward building a more potent political movement that might someday counterbalance the Islamists.
‘'Nothing tangible will come of today, and I don’t think anything tangible with happen with the elections,’’ said Ayman Roshdy, 57, a retired marketing consultant. ‘‘But there is hope. What is happening today is part of the process of building hope.
''The Islamists have been saying that they are the good guys,’’ he continued. ‘‘Now they are in control and they are being exposed by the minute. And we are building a political movement that will help us to produce a reasonable government.’’
By late afternoon, other marches from around the city, some led by well-known leaders of the political opposition, were streaming toward the square and the crowd was expected to swell by nightfall, along with the potential for more violence.