Police clashed with protesters today in the fifth consecutive day of street violence in Egypt.
Riot squads fired tear gas at rock-throwing protesters near Tahrir Square in Cairo a day after Egypt's president declared a state of emergency in three provinces.
Activists in the three areas affected have pledged to defy the curfew that will start at 9pm and will last until 6am.
Thousands of protesters had taken to the streets in Port Said, Ismailiya and Suez late on Sunday to reject President Mohammed Morsi's declaration of a 30-day state of emergency in the three Suez Canal cities and their surrounding provinces.
Those provinces had been the hardest hit by a weekend wave of unrest that has left more than 50 dead.
President Morsi warned that he would not hesitate to take more action to stem Egypt's latest eruption of violence.
"We will confront any threat to security with force and firmness within the remit of the law," the president insisted.
Mr Morsi called for a national dialogue, inviting a range of Islamist allies as well as liberal, leftist and other opposition groups and individuals to discuss the crisis.
But the opposition National Salvation Front rejected the offer.
"Unless the president takes responsibility for the bloody events and pledges to form a government of national salvation and a balanced committee to amend the constitution, any dialogue will be a waste of time," tweeted Mohamed El Baradei.
Rights activists also said that the presidential declaration was a backward step for Egypt.
Heba Morayef of Human Rights Watch in Cairo said the police would once again have the right to arrest people "purely because they look suspicious," undermining efforts to create a more 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."