Islamic hard-liners, some of them heavily suppressed under three decades of Hosni Mubarak's regime, are enthusiastically diving into Egypt's new freedoms, forming political parties to enter upcoming elections and raising alarm that they will try to lead the country into fundamentalist rule.
Some militants, taking advantage of a security vacuum, aren't waiting for the political process. They have attacked Christians and liquor stores, trying to impose their austere version of Islamic law in provincial towns.
The Islamists' newfound energy prompted the ruling military to warn last week that Egypt "will not be turned into Gaza or Iran."
Islamists could fare well in parliamentary elections scheduled for September, especially if the various groups run on a unified ticket. Their chances are boosted by the disarray among other groups.
Traditional opposition parties were deeply restricted under Mr. Mubarak's 29-year rule and have no popular base to speak of. The liberal youth groups behind the 18-day uprising that forced Mr. Mubarak to step down on Feb. 11 are still scrambling to organize before voting day.
The Islamists, furthermore, are well-funded and organized. The most established fundamentalist group, the Muslim Brotherhood, has years of experience in contesting elections.
Liberals and leftists, including the youth activists who led the protest uprising against Mr. Mubarak, are caught between their stance that all sides must be allowed to enter the political game if Egypt is to be a real democracy and worries whether Islamists will play by the rules.
"I think there is too much Islamophobia," Khaled Abdel-Hameed, one youth leader, said of fears of Islamists hijacking the process. "Everyone is trying to hijack the revolution, including me. If people elect religious groups, I will respect their choice."
Another activist, Mustafa al-Nagar, is more concerned.
"I am worried most about the Salafis, because they are not accustomed to politics," said Mr. al-Nagar, who campaigns for Mohamed ElBaradei, a Nobel Peace laureate and potential candidate in presidential elections due in November. "Their main concern is to exclude anyone else."
While the Brotherhood has long been Egypt's best organized opposition movement, the Salafis are a new player in politics.
Salafis are ultra-hard-liners, close to Saudi Arabia's Wahhabi interpretation of Islam and more radical than the Brotherhood. They seek to emulate the austerity of Islam's early days and oppose a wide range of practices they view as "un-Islamic" - rejecting the treatment of non-Muslims as citizens with equal rights, as well as all forms of Western cultural influence.
Salafis traditionally stayed out of politics, rejecting democracy because it replaces rule by God's law with the law of man. The movement grew in recent years because it was tolerated and even encouraged by the Mubarak regime to counter the Muslim Brotherhood.
With Mr. Mubarak gone, the Salafis have abandoned their disdain for politics.
Yasser Moutwaly, a Salafi leader in the Mediterranean city of Alexandria, told the Associated Press that the movement planned to set up its own party, though he insisted that entering politics would not mean abandoning its principles.
He said the Salafis and the Muslim Brotherhood were engaged in preliminary contacts over the possibility of "coordination" in the parliamentary elections.
Another contender is the Gamaa Islamiya, or the "Islamic Group," a militant organization that fought the Mubarak regime in a bloody insurgency in the 1990s, seeking to establish an Islamic state in Egypt.
It has a base of support in southern Egypt, particularly in the city of Assiut, and is conducting internal elections to create provincial and consultative councils nationwide.
Ominously, the group forced two of its veteran leaders - Karam Zohdi and Nageh Ibrahim - to resign amid criticism that they sold out to authorities when they agreed to abandon violence to win their release after serving long prison terms.
Islamists already are showing their confidence.
In Assiut, which has a sizable Christian minority, Islamists wrested control of mosques from government preachers, installing their own imams and prayer leaders.
The city is filled with signs exhorting residents to follow Islamic teachings and women to wear the hijab, or head scarf. "The hijab is obligatory," one sign says. "Take your eyes off women," another chides men.
A recent rumor that Salafis planned to attack female Muslim students at Assiut University who don't wear the head scarf, prompted some women to stay away from the 75,000-student campus for a day.
Salafis, who reject the veneration of religious shrines and tombs as a sign of idolatry, are believed to be behind the destruction of at least five Muslim shrines in the Nile Delta region the past two weeks.
They also are blamed for attacks on Christians and others they don't approve of. In one attack, a Christian man had an ear cut off for renting an apartment to a Muslim woman thought to be involved in prostitution; in another, a Muslim was killed for allegedly practicing magic, which the hard-liners denounce, a security official said.
In the oasis province of Fayoum southwest of Cairo, Salafis have forced the closure of four cafes that serve alcohol. They also set fire to four Christian homes in a Fayoum village, prompting clashes with residents, said the official, who spoke on the condition of anonymity because he was not authorized to share the information with the media.
Salafis also have threatened to destroy some of the most revered shrines in Cairo, dedicated to members of Prophet Muhammad's immediate family and beloved by many more Muslims.