A number of Egyptian opposition groups have rejected President Mohamed Morsi's call for a national dialogue following violence that has killed more than 40 people since Friday.

"Any dialogue is a waste of time if the president doesn't take responsibility for the bloody events and doesn’t vow to form a national salvation government and a balanced committee to amend the constitution," opposition leader Mohamed ElBaradei said via Twitter.

Violence erupted in a number of cities on Friday during protests to mark the second anniversary of the January 25 Revolution. Ten people, two police officers and 8 protesters, died in clashes in the canal cities of Suez and Ismailia. At least 33 protesters were also killed in Port Said in clashes with security forces since Saturday in the wake of a court verdict sentencing 21 local people to death for their role in the Port Said Stadium disaster in February 2012.

In a speech on Sunday night, President Morsi imposed a state of emergency in the three canal cities (Suez, Ismailia and Port Said) before calling on the opposition to sit down on Monday to negotiate.

Khaled Dawoud, spokesperson for the National Salvation Front (NSF), the largest opposition umbrella group, said the president's decision ignored the facts on the ground.

"If [the president] really wanted to protect lives he would have directed his government to take security measures in Port Said prior to the announcement of the verdict," he said.

Morsi had avoided taking personal responsibility for the "state of chaos" engulfing Egypt, Dawoud added.

The Egyptian Popular Current, co-founded by Nasserist former presidential contender Hamdeen Sabbahi, said Morsi's speech conveyed a limited understanding of the turbulent times Egypt is undergoing and ignored the socioeconomic and political causes for the people's anger.

The current has rejected the president's invitation for dialogue.

"Even though the Egyptian Popular Current supports constructive national dialogue, it rejects being part of a dialogue as long as the regime continues its crimes against protesters and carries out unsuccessful policies."

It called on Morsi to adopt political rather than security initiatives to solve the current crisis.

The Socialist Popular Alliance Party said it also rejected the president's offer of dialogue and called for urgent trials for those who had killed protesters, first and foremost the interior minister.

Other opposition groups seemed less hasty to reject the offer of dialogue saying they would wait for an emergency meeting of the National Salvation Front Monday at 1pm to decide.

In a statement issued on Sunday night, the liberal Constitution Party, headed by Mohamed ElBaradei, has blamed President Morsi, the Freedom and Justice Party (FJP) and the interior minister for the killing of protesters in recent days.

However, the party did not say if it would attend national dialogue talks proposed by President Morsi.

The liberal Conference Party, headed by former presidential candidate Amr Mousa, said it would decide whether to attend the dialogue after a the NSF emergency meeting.

The Strong Egypt Party, which is led by ex-Muslim Brother and former presidential nominee Abdel-Moneim Abul-Fotouh, seemed more open to dialogue.

Mohamed Osman, a leading member in the moderate Islamist party which is not a member of the NSF, told Al-Ahram's Arabic news website that the party was likely to take part in the dialogue. The party would announce its final stance on the state of emergency following the meeting, Osman added.

Islamist groups, however, have backed the imposition of a state of emergency.

Salafist Nour Party spokesman Nader Bakkar said the move was necessary but it should only be used against illegally armed citizens, not political activists.

The ultra-conservative Al-Gamaa Al-Islamiya also backed the move, saying the state of emergency was necessary to provide security for citizens in Port Said, Suez and Ismailia.

The group's political arm, the Building and Development Party, has welcomed the president's call for dialogue, saying it would participate in the interests of the nation.