AL-HOL, Syria (WASHINGTON POST) - A militant band of women loyal to the Islamic State in Iraq and Syria's (ISIS) is terrorising others who fled the battlefront for this sprawling camp in north-eastern Syria, demanding they adhere to the strict codes once enforced by the group and creating a vexing problem for the Kurdish-led forces controlling the site.

In the teeming al-Hol displacement camp, the true believers have been threatening those they consider impious, brandishing knives, spitting and throwing stones at them, and even burning down their tents.

Intelligence officials say ISIS loyalists also have formed cells inside the camp to mete out punishment in a more systematic way.

The leaders of this movement are women from countries such as Egypt, Morocco and Tunisia, which have produced some of ISIS' most militant followers in recent years, according to officials from the Syrian Democratic Forces, or SDF, the Kurdish-led troops.

While there are scores of instigators, the ranks of those who remain staunchly behind ISIS could still number in the thousands, and they are committed to upholding its ideology even as the self-declared caliphate has been brought to an end.

"We hope that the (Islamic) state will come back," said Um Aisha, 22, an Iraqi resident of the camp. "We had syariah law there. Here, there is only corruption." Covered from head to toe in black, she said she often admonishes other camp residents for failing to dress conservatively or for neglecting their prayers.

In ISIS, "they told us what was right and what was wrong. It was better," she said. "Here, people wear whatever they want."

As the US-backed Kurdish troops battled in recent weeks to capture the final ISIS stronghold in the eastern Syrian village of Baghouz, thousands of people fled the fighting. The SDF separated the men, sending them to detention centres. Women and children were transported to the al-Hol displacement camp, which has seen its population explode since early December from 9,000 people to more than 73,000.

"What we did is we took Baghouz and we brought it here," said Mahmoud Gadou, a Kurdish official responsible for displaced people in north-east Syria.

ISIS once held a vast swath of territory across Syria and Iraq, where militants committed horrific atrocities, including mass executions and sexual slavery. The group also lured recruits from around the world, promising them an Islamic utopia where they could openly practice their faith.

"When people began to arrive at the camp from Baghouz, the atmosphere changed 180 degrees," said Gadou. Before that, when the camp hosted roughly 10,000 Syrians and Iraqis, "women weren't covering their faces. Now, you can't see a girl older than 8 without a veil," he said.

Many of those who adopted more-conservative dress are afraid, officials say, and want to avoid harassment from ISIS followers. Others have been persuaded by the group's adherents.

"Some of these people came from areas that were already conservative, even if they didn't support ISIS," said Mohamed Bashir, head of public relations for the camp's Kurdish-led administration. "But now, they are even more extreme. The tensions are high."

The militant women have targeted health staff and aid workers, calling them "infidels." In one case cited by an aid official, they threw excrement at a man extracting sewage from a latrine in the camp annex hosting foreigners. Some women also have used the sharp edges of tuna cans to cut into tents and attack others, including those who have expressed regret about joining the caliphate.

In a recent incident at the camp's market, a knife-wielding woman threatened a man wearing a shirt with an English-language slogan, Gadou said, and both men and women are often reprimanded by the extremists for behaving inappropriately by violating their harsh interpretation of Islamic law.

While Kurdish forces say they have arrested some of the worst offenders, including those who burned tents, officials acknowledge they cannot protect everyone at al-Hol.

Some women were too intimidated by the true believers to discuss the tensions at the camp or whether they had been targeted.

A German woman, who spoke on the condition she not be named, said she had travelled to the Middle East to live under ISIS, in part, because she used to be accosted in Germany for wearing the niqab, a black veil that covers the face.

"At the time, it was the right decision for me," she said. "But now, I don't know," she added, her voice trailing off before she decided not to speak further.

"I can't talk about this," she said, explaining she did not want to anger ISIS loyalists at the camp.

Gaylon Su, from the dual-island Caribbean nation of Trinidad and Tobago, said she was never a supporter of ISIS. She said she travelled to Syria with her husband soon after converting to Islam in 2014. She stays in a segregated section of the camp reserved for thousands of women from outside Syria and Iraq.

They treat her harshly.

"They hate me," Su, 45, said of the extremists around her. "It's hard here. I don't have any friends. I am an infidel to them." Many have pledged to resurrect the caliphate should they ever be released.

"To live in the caliphate, it was such a beautiful thing," said Um Safia, a 27-year-old French woman from the city of Marseille. "We want to live under Islamic law," she said, adding that she prays for ISIS' return. Even when she held her dying daughter in her arms in Baghouz, she said, her faith was unshaken.

Camp officials worry the squalid encampment, which is facing an escalating humanitarian crisis, could become a breeding ground for further extremism.

"We have two kinds of extremists. First, there are the ones who will die before coming to us for help," said Dilovan, a Kurdish intelligence official at the camp who declined to give her full name for security reasons.

"The second kind are the ones who have accepted their current reality," she said. "But if they got the opportunity to attack us or break free, they would take it."

On a recent day, dozens of foreign women were pressed up against the chain-link fence that cordons them off from the rest of the camp. They shouted at the armed Kurdish guards watching over them.

"They treat us like dogs!" yelled one woman, who said she was from Russia.

Another woman, who spoke in a North African dialect of Arabic, shoved one of the members of the security forces, even as she cradled an infant. "You have a big gun, but we are not afraid of you!" she shouted.

Away from the scuffle, 27-year-old Hanifa, who said she is from Russia's Dagestan region, spotted a woman without a face veil.

"I don't like this," she said. "Women should cover their faces."