The political crisis in Egypt and the ongoing unrest could lead to "the collapse of the state," Defence Minister and army chief Abdel-Fattah al-Sissi warned Tuesday, dpa reported.
"The continuation of conflict between the various political forces and their differences over how the country should be run could lead to the collapse of the state and threatens future generations," he said.
There have been riots across the country for the past five days, with protesters blaming Islamist President Mohammed Morsi for not achieving the goals of the revolution.
"The continuation of this scene without solution from all parties leads to serious consequences affecting the stability of the country," al-Sissi said. "But the Egyptian army will remain the consistent and solid pillar of state."
Some 50 people have died in the clashes since Friday, when thousands were marking the second anniversary of the revolt that toppled president Hosny Mubarak.
Thousands of demonstrators took to the streets late Monday in Cairo and the coastal city of Alexandria. Mass marches also took place in the three restive cities of Port Said, Ismailia and Suez, where Morsi imposed a state of emergency and a night-time curfew.
Black smoke enveloped central Cairo when anti-government protesters set fire to police vehicles, as security officers prevented them from reaching parliament.
In Ismailia, residents organized street football matches to defy the curfew, local media reported.
There were no reports of arrest by troops deployed in Suez and Port Said, although the legislature approved a govenment proposal to give the army the power to arrest civilians.
The opposition rejected an invitation for a dialogue with Morsi and threatened to call for early presidential elections if their conditions - which include a new government, amending the constitution and disbanding the Islamist-dominated parliament - are not met.