Egypt's Interior Ministry has urged supporters of ousted President Mohamed Morsi to leave their Cairo protest camps, offering "a safe exit" to protesters.

In a statement read on state television Thursday, the ministry called "on those in Rabaa al-Adawiya and Nahda squares to let reason and the national interest prevail, and to quickly leave." The call came one day after the army-backed government ordered the ministry to take action against protesters.

The ministry said police commanders met to study how to move in against the protest camps, amid mounting international calls for restraint. There is no specified date for clearing out the sit-in.

On Tuesday, the military-backed interim government declared the two Cairo vigils "unacceptable threats" to national security. Authorities directed police to stay within the law when they end the sit-ins.

Morsi's Muslim Brotherhood movement said the military may be setting up the demonstrators for what it fears could be another massacre. Security forces shot at demonstrators in Cairo Saturday, killing at least 80 people.

Protesters are occupying squares outside the Rabaa al-Adawiya mosque in eastern Cairo and the city's main university campus.

Nearly 200 people have been killed since the Egyptian military toppled Morsi from power on July 3. His supporters are demanding his return to the presidency and the restoration of the Islamist-drafted constitution.

The country's interim government plans to hold a referendum within five months to ratify amendments to the constitution. Parliamentary elections would take place early next year followed by a new presidential election.