An image grab taken from Egyptian state TV shows Egypt's army chief, Gen. Abdel Fatah al-Sissi, giving a live broadcast calling for public rallies this week to give him a mandate to fight "terrorism and violence." (Egyptian TV via AFP)

When Egyptian military chief and coup leader Gen. Abdel Fatah al-Sissi called, in a speech broadcast by state media Wednesday, for Egyptian demonstrations to "come out to give me the mandate and order that I confront violence and potential terrorism," many heard something more than a call for peaceful protest against terrorism. Some worried that the speech was meant to build public support for a campaign against the Muslim Brotherhood or even as a dog whistle call for mass mobilization against the Islamist group.

"I’ve never asked you for anything," Sissi declared, wearing dark sunglasses and full military dress. "I’m asking you to show the world. If violence is sought, or terrorism is sought, the military and the police are authorized to confront this."

Since ousting President Mohamed Morsi, an Islamist, in early July, the military has cracked down on the Muslim Brotherhood, arresting some of its most senior members. Several pro-Morsi protesters have been killed in clashes. Animosity between the Brotherhood and the military, both of which have deep bases of support in Egyptian society, goes back decades. Some analysts suspect that Sissi is hoping that, just as mass protests against Morsi paved the way for the military's coup, another round of demonstrations against "terrorism" may provide justification for a further crackdown on the Brotherhood. The military, since taking power in early July, has portrayed Egyptian Islamists as terrorists.

Tamarod, a protest collective that helped organize this summer's anti-Morsi protests, posted a message on Facebook calling for Egyptians to heed Sissi's calls for demonstrations as a way to "support the Egyptian armed forces in the coming war against terrorism and cleansing the land of Egypt."

Violence is indeed worsening in Egypt, and apparently not just from the military. Late on Tuesday, a bomb exploded outside a police station, killing one and wounding 19 others, and raising fears that some Islamists may resort to violence. The attack brings the total death toll since Morsi's ouster to perhaps 190.

Gehad el-Haddad, a spokesman for the Muslim Brotherhood, warned on Twitter that he believed Sissi's speech was a call for mass violence against the Brotherhood. While Haddad has been known to exaggerate, he may not be the only member of the Islamist group who fears persecution from the military.

While many Egyptians opposed the military's heavy-handed rule in the first months after it ousted President Hosni Mubarak in early 2011, military leaders appear to be more carefully cultivating populist support this time. Air force jets have flown over crowds in Tahrir Square and army helicopters have dropped flags over protests.

As Egypt analyst Shadi Hamid has written, coups tend to produce a legitimacy crisis, requiring the new government to enforce or cultivate political legitimacy through other means. In this case, that may mean justifying its rule as a necessary response to the threat from Islamist "terrorists."

Sissi asked for the demonstrations to gather Friday. We'll be following it then so please do check back.