Campaigners demanding a swifter transition to civilian rule have called for mass walkouts and civil disobedience on February 11.
At least 15 people have died in street fighting in Cairo and the eastern city of Suez in recent days, unrest provoked by the death of 74 people after a soccer match.
The ruling military council issued a statement saying it would send patrols across the country to “maintain the security … of public, private and state buildings”.
Lieutenant General Sami Enan, the armed forces chief of staff, urged Egyptians to “protect the security and stability of the country through work and production,” the state news agency MENA reported.
Prime Minister Kamal al-Ganzouri told a conference that calls for civil disobedience were part of a plan to “overthrow the state …” and said all Egyptians should unite to get through the crises and dangers the country was facing.
Al-Azhar, a prestigious seat of Sunni Muslim learning, also criticised the calls for civil disobedience, the state-owned al-Ahram news portal reported, and MENA said that Pope Shenouda, head of the Orthodox Coptic church, had said civil disobedience was against religion.
The head of the military council, Mohamed Hussein Tantawi, called earlier this week for plans for the first post-Mubarak presidential election, currently scheduled for June, to be completed quickly.
Elections for the lower house of parliament have been completed and those for the upper house are under way. The armed forces have said they will hand over power to civilian authorities after the presidential poll.
Some Egyptians accuse the army of blocking real reform of the security forces, which enjoyed virtual impunity under Mubarak.