Egyptian President Mohammed Mursi has declared a month-long state of emergency in three cities along the Suez Canal.
The region has been the focus of anti-government violence that has killed dozens of people over the past four days.
Seven people were shot dead and hundreds were injured in Port Said during the funerals of 33 protesters killed at the weekend.
A total of 49 people have been killed in demonstrations around the country since Thursday and Mr Mursi's opponents have called for further protests in the week ahead.
In a televised address, Mr Mursi said a nightly curfew would be introduced in Port Said, Ismailia and Suez, starting on Sunday.
He also called for dialogue with top politicians.
About 200 people protested in Ismailia after the announcement.
"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," the president said, adding that he offered condolences to families of the victims of those who died in the cities.
In Cairo the newly appointed interior minister Mohamed Ibrahim was ejected from the funeral of one of the police officers who died during clashes in Port Said, according to witnesses and police sources.
A police officer at the funeral said many of his colleagues blame the interior minister for the deaths of at least two policemen during clashes as he did not allow the police there to carry weapons and were only given teargas bombs.
State television said seven people died from gunshot wounds today. Port Said's head of hospitals, Abdel Rahman Farag, told Reuters more than 400 people had suffered from teargas inhalation, while 38 were wounded by gunshots.
Gunshots had killed many of the 33 who died when residents went on the rampage after a court sentenced 21 people, mostly from the Mediterranean port, to death for their role in deadly soccer violence at a stadium there last year.
A military source said many people in Port Said, which lies next to the increasingly lawless Sinai Peninsula, possess guns because they do not trust the authorities to protect them. However it was not clear who was behind the deaths and injuries.
In Cairo, police fired teargas at dozens at protesters throwing stones and petrol bombs in a fourth day of clashes over what demonstrators there and in other cities say is a power grab by Islamists two years after Hosni Mubarak was overthrown.
In Ismaila city, which lies on the Suez Canal between the cities of Suez and Port Said, police also fired teargas at protesters attacking a police station with petrol bombs and stones, according to witnesses and a security source there.
The protesters accuse Mr Mursi, elected in June with the support of his Muslim Brotherhood group, of betraying the democratic goals of the revolution. Most of the deaths since Thursday were in Port Said and Suez, both cities where the army has now been deployed.
The violence adds to the daunting task facing Mr Mursi as he tries to fix a beleaguered economy and cool tempers before a parliamentary election expected in the next few months which is supposed to cement Egypt's transition to democracy.
It has exposed a deep rift in the nation. Liberals and other opponents accuse Mr Mursi of failing to deliver on economic promises and say he has not lived up to pledges to represent all Egyptians.
His backers say the opposition is seeking to topple Egypt's first freely elected leader by undemocratic means.
Heba Morayef of Human Rights Watch in Cairo said a state of emergency reintroduced laws that gave police sweeping powers of arrest "purely because [people] look suspicious".
"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."
The opposition Popular Current and other groups have called for more protests today to mark what was one of the bloodiest days of the 2011 uprising.