When the women's militia of an Al Qaeda splinter group recently raided a high school in the northern Syrian city of Raqqah, it found a range of violations of its strict interpretation of Islam.
Ten young women were deemed guilty of donning a face veil that was too transparent, having visible eyebrows or wearing a hair clip under her hijab, or head covering. Each student was whipped 30 times, said one opposition activist, who asked to remain unidentified because he is wanted by the Islamic State of Iraq and Syria, the militant group that until recently was affiliated with Al Qaeda.
Even as it is pushed out of many northern Syrian towns by other opposition forces fed up with its aggression and extremist tactics, the group, also known as ISIS, has created a stronghold in Raqqah province and is seeking to establish an Islamic caliphate ruled by harsh religion-inspired edicts.
Music and smoking have been banned, Internet cafes frequently raided and a protection tax levied on Christian residents.
Women must wear the hijab and niqab, or full-face veil. Muslim prayer is mandatory and businesses must be shuttered during the five daily prayer times, said current and former residents interviewed via Skype.
"When prayer is called, people rush to close their shops and go to mosque and women run to hide," said Ghaith Fakhri, a "citizen journalist" who left Raqqah in January because he was wanted by ISIS.
Public executions now take place for offenses including accusations of cursing the prophet Muhammad or God, residents and activist groups said.
About a third of the population has fled the province in the last two months, chafing under the Islamist rule, Fakhri said.
Formation of ISIS was announced last year in Raqqah when Abu Bakr Baghdadi, then the leader of the Al Qaeda-linked Islamic State of Iraq, expanded into neighboring Syria. Fighters with other rebel militias began pledging allegiance to Baghdadi, and the group quickly spread across northern Syria.
In early January, opposition groups including the Free Syrian Army and Islamist rebels launched an offensive against ISIS, which at times had fought alongside other rebels and other times against them. Two weeks ago, ISIS withdrew from more than a dozen towns in Aleppo and Hasaka provinces in one day.
In Raqqah though, rival rebel groups that were outnumbered and outgunned retreated after several days of fierce fighting, leaving the entire province under ISIS control except for two Syrian government military bases and an airport.
In February, Al Qaeda's central command announced it had severed ties with ISIS. But a year after Raqqah fell under opposition control and was hailed as "the first capital of Free Syria," ISIS has become more entrenched and emboldened there.
"In Raqqah, they have had a much longer time to consolidate their presence," said Aymenn Jawad Tamimi, a Shillman-Ginsburg fellow at the Middle East Forum and a columnist at Jihadology.net.
Last month, ISIS announced it had ordered Christians in Raqqah to pay jizya, a tax levied on non-Muslims. In addition, Christians were barred from building or rebuilding churches, wearing crosses or engaging in public prayer. But many in Raqqah termed the announcement a publicity stunt to draw attention to ISIS' establishment of a caliphate because so few Christians are left in the province.
Most of the small Christian population left last year when rebels first took the city from government forces, Fakhri said. Most of those who remained fled once ISIS solidified its control. About a dozen Christian families are left in Raqqah city and a few more in the border town of Tal Abyad, he said.
ISIS has threatened Christian residents' existence in other ways as well.
One Christian family Fakhri knows was told to either convert to Islam or have its property confiscated, he said. The family chose to convert rather than lose its home.
Last fall, the two churches in Raqqah city were taken over by ISIS, which removed the crosses, broke the bells and put up black ISIS flags. Now the buildings serve as proselytizing centers for the Islamist group.
Underscoring its ambitions of a global caliphate, an official ISIS Twitter account recently tweeted, "Today in Raqqah and tomorrow in Rome."
Much like the government of Syrian President Bashar Assad, ISIS has taken to governing through fear and an iron fist, activists and residents said.
"In the streets you see ISIS' foreign fighters more than you see Raqqah's own residents," said an activist from the opposition Tahrir Syria group, who requested anonymity for security reasons. "They raid homes and Internet cafes and neighborhoods. They have spies among cafe owners."
ISIS has also taken over government buildings and banks, he said. Some of the city's luxury hotels have been turned into living quarters for the group's foreign fighters, who come from Europe, North Africa and Central Asia.
Homes that were bought with a mortgage, forbidden under Islam if it involves interest, have been seized by ISIS, the Tahrir Syria activist said.
A sharia court metes out justice according to strict Islamist laws.
"They don't care about pacifying or appeasing the population because they don't have any popular support anyway," Fakhri said. "For them it is that they are right and we are wrong, that's it."
Most humanitarian nongovernmental organizations no longer send aid convoys to Raqqah to avoid associating with a blacklisted terrorist organization, one activist said. ISIS has banned shipments of medicine and has monopolized the drug business, charging pharmacies inflated prices, according to the Masar Press Agency, an opposition media group.
Rebels from surrounding provinces have mostly turned their attention away from fighting ISIS in order to battle pro-government forces. Some opposition groups have said they will go after ISIS in Raqqah in an attempt to push it out of Syria, but that prospect seems unlikely for now because weapons and fighters are already stretched thin.
Meanwhile, ISIS continues to consolidate its power in the province of about half a million people.
"They are getting stronger," said the Tahrir Syria activist. "If they want to get ISIS out of Raqqah it will be very hard."