Raising his voice and sternly wagging his finger, Egyptian President Mohamed Morsy said late Sunday that he won't stand by in the wake of recent violence, declaring a limited state of emergency and suggesting more such moves could be in the offing.

"I will act, and now I am acting," the defiant Morsy said in a nationally televised speech.

Morsy -- who became the North African nation's first democratically elected president last year but since has become a target of critics accusing him of amassing power for himself and his conservative allies -- imposed a 30-day curfew in Port Said, Ismailia and Suez. Under his order, people in those governorates cannot go out between 9 p.m. to 6 a.m.

The three northeastern Egyptian cities, all of them along the Suez Canal, have been sites of deadly violence in recent days.

It began Friday when protesters angry with Morsy's regime clashed with government supporters and police in Suez, Ismailia and elsewhere.

Then on Saturday and Sunday, 38 people died and more than 630 were injured in Port Said, where a riot broke out after news broke that 21 people from Port Said had been sentenced to death for their roles in a bloody 2012 riot at the coastal city's soccer stadium.

In his Sunday night speech, Morsy claimed people in these and other places had attacked public and private institutions, "terrorized civilians," blocked roads and taken up arms.

Those "criminals" responsible will face "justice as soon as possible," the president said. He added he has instructed the Interior Ministry, which oversees security forces, "to deal properly, and also with force, against those who attack the nation's institutions."

"We will deal with them severely," he said, insisting Egyptian authorities are capable of restoring peace and security.

The president invoked the so-called January 25 Revolution, the popular uprising two years ago that led to the ouster of longtime leader Hosni Mubarak.

Many of those who hit the streets on Friday did so to rail against Morsy, a former Muslim Brotherhood leader. At one point, Morsy declared himself immune from judicial oversight and pushed through a new constitution, actions his critics say were reminiscent of Mubarak.

On Sunday, the president said some demonstrators' violent "behavior does not have anything to do with the Egyptian revolution. ... In fact, it is against the revolution."

At the same time, he acknowledged the legitimate dissent in Egypt, as well as its impact on the country, and said "dialogue is the only way to bring about stability and security."

To this end, he invited representatives from 11 political parties to a meeting Monday. His spokesman, Yasir Ali, told state-run Nile TV that this meeting "is meant to address problems in Egypt, as opposed to express anger."

It's a sentiment that Morsy himself expressed a short time earlier, saying dialogue amongst various Egyptians was the only way for the country to reach peace and prosperity.

"We are going that way, all together," he said. "God bless Egypt, and make her safe for her people and the whole world."

Troops try to restore calm in Port Said

Roads in and out of Port Said, which sits along the Mediterranean Sea at the northern entrance of the Suez Canal, were shut down Sunday as authorities tried to maintain calm after the previous day's bloodshed.

It all stemmed from a February 1, 2012, riot at the close of a match between Cairo's prestigious Al-Ahly football club and the host Al-Masry team.

That day, 73 people were killed and more than 1,000 wounded in violence between supporters of the two teams. Many died falling from bleachers inside the stadium, while others suffocated.