CAIRO (AP) -- Egypt's military moved swiftly Thursday against senior figures of the Muslim Brotherhood, targeting the backbone of support for ousted President Mohammed Morsi. In the most dramatic step, authorities arrested the group's revered leader from a seaside villa and flew him by helicopter to detention in the capital.
With a top judge newly sworn in as interim president to replace Morsi, the crackdown poses an immediate test to the new army-backed leadership's promises to guide Egypt to democracy: The question of how to include the 83-year-old fundamentalist group.
That question has long been at the heart of democracy efforts in Egypt. Hosni Mubarak and previous authoritarian regimes banned the group, raising cries even from pro-reform Brotherhood critics that it must be allowed to participate if Egypt was to be free. After Mubarak's fall, the newly legalized group vaulted to power in elections, with its veteran member Morsi becoming the country's first freely elected president.
Now the group is reeling under a huge backlash from a public that says the Brotherhood and its Islamist allies abused their electoral mandate. The military forced Morsi out Wednesday after millions of Egyptians nationwide turned out in four days of protests demanding he be removed.
Adly Mansour, the head of the Supreme Constititonal Court, with which Morsi had repeated confrontations, was sworn in as interim president.
In his inaugural speech, broadcast nationwide, he said the anti-Morsi protests that began June 30 had "corrected the path of the glorious revolution of Jan. 25," referring to the 2011 uprising that toppled Mubarak.
To cheers from his audience, he also praised the army, police, media and judiciary for standing against the Brotherhood. Islamists saw those institutions as full of Mubarak loyalists trying to thwart their rule.
Furious over what it calls a military coup against democracy, the Brotherhood said it would not work with the new leadership. It and harder-line Islamist allies called for a wave of protests Friday, dubbing it the "Friday of Rage," vowing to escalate if the military does not back down.
There are widespread fears of Islamist violence in retaliation for Morsi's ouster, and already some former militant extremists have vowed to fight.
Suspected militants opened fire at four sites in northern Sinai, targeting two military checkpoints, a police station and el-Arish airport, where military aircraft are stationed, security officials said. The military and security responded to the attacks, and one soldier was killed and three were injured, according to security officials who spoke on condition of anonymity because they were not authorized to speak to the media.
Multiple officials of the Brotherhood firmly urged their followers to keep their protests peaceful. Thousands of Morsi supporters remained massed in front of a Cairo mosque where they have camped for days, with line of military armored vehicles across the road keeping watch.
"We declare our complete rejection of the military coup staged against the elected president and the will of the nation," the Brotherhood said in a statement, read by senior cleric Abdel-Rahman el-Barr to the crowd outside the Rabia al-Adawiya Mosque in Cairo.
"We refuse to participate in any activities with the usurping authorities," the statement said, urging Morsi supporters to remain peaceful. The Rabia al-Adawiya protesters planned to march Friday to the Ministry of Defense.
The Brotherhood denounced the crackdown, including the shutdown Wednesday night of its television channel, Misr25, its newspaper and three pro-Morsi Islamist TV stations. The military, it said, is returning Egypt to the practices of "the dark, repressive, dictatorial and corrupt ages."
A military statement late Thursday appeared to signal a wider wave of arrests was not in the offing. A spokesman, Col. Ahmed Mohammed Ali, said in a Facebook posting that that the army and security forces will not take "any exceptional or arbitrary measures" against any political group.
The military has a "strong will to ensure national reconciliation, constructive justice and tolerance," he wrote. He spoke against "gloating" and vengeance, saying only peaceful protests will be tolerated and urging Egyptians not to attack Brotherhood offices to avert an "endless cycle of revenge."
The army's removal of Morsi sparked massive celebrations Wednesday night among the crowds of protesters around the country, with fireworks, dancing and blaring car horns lasting close to dawn.
The constitution, which Islamists drafted and Morsi praised as the greatest in the world, has been suspended. Also, Abdel-Meguid Mahmoud, the Mubarak-era top prosecutor whom Morsi removed to much controversy, was reinstated to his post and immediately announced investigations against Brotherhood officials.