Clashes between protesters and Egypt’s security forces continued in Port Said while demonstrators defied President Mohamed Morsi’s curfew order in the cities of Ismailia and Suez, state media reported early Tuesday.

Egyptian troops thwarted an attempt by a group of gunmen to storm a prison in Port Said, CNN reported from Cairo. State news agency MENA reported six deaths in Port Said on Monday. At least 38 people, including civilians and soldiers, have been killed there in the past two days, according to CNN. State media said 590 people were injured in violence across Egypt on Monday, most of them in Port Said.

In the port city of Alexandria, 160 miles west of Port Said, protesters sat on train tracks, disrupting rail travel. In Suez, 100 miles to the south, people marched towards the headquarters of the provincial government and subsequently clashed with security forces.

Meanwhile, Egypt’s main opposition alliance rejected Morsi’s renewed call for a national dialogue to put an end to the political impasse and street violence.

The National Salvation Front (NSF), a coalition of liberal opposition parties and groups in Egypt, rejected the president’s initiative at a press conference a few hours before the dialogue started Monday, Egypt’s Al Ahram newspaper reported.

Mohamed ElBaradei, an NSF leader and former chief of the International Atomic Energy Agency, called on the president to appoint a unified government and take steps to amend the disputed constitution, BBC reported.

"The dialogue to which the president invited us has to do with form and not content," ElBaradei said. "We support any dialogue if it has a clear agenda that can shepherd the nation to the shores of safety."

The opposition demands include replacing the incumbent cabinet with a coalition government, setting up of a committee to amend the constitution drafted by an Islamist-dominated Constituent Assembly and appointing a new prosecutor-general.

In a televised address late Sunday, Morsi declared a 30-day state of emergency in Port Said, Suez and Ismailia, the three provinces which have witnessed deadly clashes since the second anniversary of the Egyptian revolution Jan. 25.

A court ruling Saturday, issuing death sentences for 21 people from Port Said for their roles in a football game riot last year, ignited further violence.