Monday in Cairo could become more chaotic than usual if the military moves forward with a plan to confront protesters staging sit-ins across the city demanding that deposed President Mohammed Morsi be returned to power.

"State security troops will be deployed around the sit-ins by dawn as a start of procedures that will eventually lead to a dispersal," a senior security source told Reuters.

Whether this means violence or not depends on how much the military is heeding the advice of some government officials and mediators not to resort to force to break up the impromptu encampments, which have swelled during the Eid al Fitr holiday marking the end of the Muslim fasting and reflection month of Ramadan. Some recent protests number into the tens of thousands of demonstrators at times, so the likelihood of clashes remains high.  

Supporters of Morsi, who became president last year in what is widely considered to have been Egypt’s cleanest presidential election in its history, and his Muslim Brotherhood Party, an 85-year-old Islamic conservative political organization, rallied on Sunday ahead of the expected confrontation.

At one march in central Cairo, Al-Jazeera reported that women were seen chanting "Sisi is a traitor, Sisi is a killer,” referring to General Abdul Fatah al-Sisi, who effectively took control following a July 3 military coup.  Another demonstration in an east Cairo neighborhood involved a convoy of honking passenger cars and trucks displaying images of Morsi.

Meanwhile, the pro-Islamist pro-democracy civilian backlash might be emboldening both the military and Islamist militants in the Sinai Peninsula near Israel. Two hundred miles northeast of Cairo near the shores of the Mediterranean and the border with the Gaza Strip, an overnight raid killed at least 12 and injured 13 other armed suspected militants in the town of Sheikh Zuweid.

Egyptian military spokesman Ahmed Ali told Al-Jazeera on Sunday the men were aligned with militant groups “terrorizing the innocent citizens of North Sinai” and were at a “weapons depot” that was destroyed in the assault. The predominate militant group operating in North Sinai is Ansar Beit al-Maqdis, which claims the Egyptian government is colluding with Israel to attack them.

On Saturday, the bodies of four men killed a day earlier in an Egyptian military helicopter attack were paraded through North Sinai villages amid a convoy waving black flags emblazoned with the Islamic shahada creed, a common banner used by Islamist militants throughout the Middle East. Early reports said the attacks were conducted by Israeli drones; the Egyptian military denies this and says it was responsible for the attack that killed the four men. 

The border between Gaza and the Sinai has been the focus of intense scrutiny over the years as a source of passage for weapons fed to Hamas militants. Egypt has worked with both Israel and the U.S. to enforce an embargo and cut off tunnels used to transport much needed goods into Gaza, but the tunnels also have been used to channel weapons and militants.

Egypt’s participation enforcing a years-long blockade of the Gaza Strip has been used by militants to gin up support against Cairo among the remote towns of the Sinai and elsewhere in Egypt. Attacks by antigovernment militants in North Sinai have escalated since the Arab Spring revolutions.