Egypt's ruling military warned on Friday it would "deal firmly" with any attempt to harm the public interest, and blamed political divisions on the release of unofficial presidential poll results by candidates.
"Protecting the status of state institutions is a national responsibility for all: any attack on them threatens the stability and national security of Egypt," said a Supreme Council of the Armed Forces statement read on state television.
"Any attempts to harm public or private interests will be confronted with utmost firmness and strength by the police and armed forces within the law," SCAF said.
The statement was issued as thousands of people packed Cairo's Tahrir Square to denounce what they said was a power grab by the army ahead of the naming of a new president following a highly divisive poll.
But the SCAF defended a constitutional document giving it legislative powers, control over the new constitution and a broad say in government policy.
"The issuing of a constitutional declaration was a necessity imposed by the needs of managing the affairs of the country during the current critical phase of the history of our nation," the military council said.
It instead blamed the tension in Egypt on the release of unofficial poll results.
"The early release of the presidential election results, before the announcement by the responsible body, was unjustified and is one of the main reasons for divisions and tensions in the political arena," SCAF said.
Its comments appeared to be directed at the powerful Muslim Brotherhood, which said that its candidate Mohamed Morsi had won the election, providing what it said were certified copies of ballot tallies to bolster its claims.
Morsi's rival Ahmed Shafiq also claimed victory, and told reporters on Thursday he was confident he would be declared Egypt's "legitimate" president.
A delay in the run-off results, which had been due on Thursday, raised widespread suspicions that the result was being negotiated rather than counted.
But the SCAF insisted in its statement that it stood "at equal distance" from all political forces and called on all to respect the results.
"National responsibility requires all political forces to... abide by the rules of the democratic process," SCAF said.