With U.S. Marines gone and central government authority virtually nonexistent, Fallujah resembles an Islamic mini-state - anyone caught selling alcohol is flogged and paraded in the city. Men are encouraged to grow beards and barbers are warned against giving "Western" hair cuts.
"After all the blood that was shed, and the lives that were lost, we shall only accept God's law in Fallujah," said cleric Abdul-Qader al-Aloussi, offering a glimpse of what a future Iraq may look like as the U.S.-led occupation draws to a close. "We must capitalize on our victory over the Americans and implement Islamic sharia laws."
The departure of the Marines under an agreement that ended the three-week siege last month has enabled hard-line Islamic leaders to assert their power in this once-restive city 30 miles west of Baghdad.
Some were active in defending the city against the Marines and have profited by a perception - both here and elsewhere in Iraq - that the mujahedeen, or Islamic holy warriors, defeated a superpower.
Under the agreement, the Marines handed security in the city to a new Fallujah Brigade made up largely of local residents and commanded by officers of Saddam Hussein's former army.
With the departure of the Marines, the position of the U.S.-appointed civil administration has been weakened in favor of the clerics and the mujahedeen who resisted the U.S. occupation. That is a pattern that could be repeated elsewhere in Iraq after the occupation ends June 30, unless other legitimate leaders come forward to replace those tainted by association with the occupation.
Fallujah, which calls itself the "City of Mosques," provides the religious fundamentalists with fertile ground for wielding power. The city's estimated 300,000 residents are known for their religious piety.
Women rarely appear in public and when they do, they are covered from head to toe in accordance with Islam's strict dress code for women. The lives of men revolve around Islam's tradition of praying five times a day.
Unlike other Iraqi cities, Fallujah has never allowed liquor stores. Its famous kebab restaurants have prayer rooms, an unusual feature in most Muslim nations. Many of its adult male population wear beards, a hallmark of religious piety.
However, steps taken by the mujahedeen over the past month have gone beyond simply encouraging piety.
On Sunday, for example, scores of masked mujahedeen, shouting "Allahu Akbar," or "God is Great," paraded four men stripped down to their underpants atop the back of a pickup truck that drove through the city. Their bare backs were bleeding from 80 lashes they had received as punishment for selling alcohol. They were taken to a hospital where they were treated and released.
Residents said a man found intoxicated last week was flogged, held overnight and released the next day.
Fallujah's women hair stylists shut down their shops several months ago after repeated attacks blamed on Muslim militants.
On Tuesday, the mujahedeen expanded their "clean up" campaign. About 80 masked, armed men, accompanied by local police, forced hundreds of street hawkers at gun point to clear out from the streets and confine their businesses to designated areas.
The masked men later moved to the city's used car market and "persuaded" dealers to move away from the city center because they were blocking traffic. In both cases, the police stood by without intervening.
According to residents, barbers have been instructed not to give "Western" haircuts - short on the back and sides and full on top - or to remove facial hair. Four youths with long hair were stopped at a market by mujahedeen on Sunday and marched to a public market where they were shorn.
"Are we Muslims, or not?" asked Abdul-Rahman Mahmoud, a 40-year-old father of three. "We are. So, we must apply God's laws. The mujahedeen's word is heard and respected, and the same goes for our clerics."
There is little sign of opposition to the mujahedeen, though it could be that some people are simply afraid of confronting armed men.
Sheik Omar Said of the Fallujah branch of the Association of Muslim Scholars, a Baghdad-based organization created last year to defend the rights of the Sunni Arab minority, insists that nearly everyone in Fallujah really wants Islamic law.
However, he hinted that perhaps in some cases, the mujahedeen have gone too far.
"This will only come after educating society in religious matters first and then moving on to applying Islamic punishments," he said.
However, the mujahedeen are clearly profiting from the hero status they acquired during the April battles against the Marines.
There is even talk of building a museum dedicated to the "struggle" against the American occupation. Money has been collected in recent weeks to help the families of those who died in the fighting, said by the locals to number 1,000 "martyrs."