Some women in Islamic State (ISIS/ISIL)-controlled Mosul have said they are “much more afraid” of the jihadist group’s all-female “morality police,” or Khansaa Brigade, than the battle-hardened male terrorists, reports NBC News.

The all-female units of the jihadist group’s “morality police,” also known as Hisbah, had been tasked with patrolling the streets of Mosul and enforcing an extreme version of Shariah law.

Members of the Hisbah Khansaa Brigade favor a torture tool known as “the biter,” which refers to “metal prongs designed to clip chunks of flesh as punishment for women who violated strict ISIS’ dress codes,” NBC News learned from Umm Azma, a 31-year-old mother of eight.

“They used this on my neighbor who was cleaning in front of her house without the headscarf,” added Azma, gesturing to her own upper arm to show where the tool had been used. “Then they took her away for lashings. She never came back.”

Currently, ISIS jihadists in Mosul, Iraq’s second largest city and the terrorist group’s last major stronghold in the country, are under siege by a U.S.-backed force of Iraqi troops and their allies.

Officers from the all-women religious enforcement units in Mosul have been dictating where other females could go and what they could wear since ISIS captured the city in 2014.

“I was much more afraid of women,” Umm Fatma, referring to Khansaa Brigade, told NBC News after she arrived at the Khazer Camp in Iraq last week as one of the tens of thousands of refugees fleeing Mosul.

“The women would beat you for the smallest thing — how you looked or how you wore your headscarf,” added the 28-year-old mother. “They used whips and metal sticks.”

NBC News notes that it has not been able to independently verify the Iraqi women’s accounts of torture at the hands of the all-female ISIS units, but added that it has spoken to “several” female refugees who have shared similar stories.

In April, Human Rights Watch reported on the female units and the torture device, identified by Azma as “the biter.”

Moreover, earlier this year, rebel fighters affiliated with the U.S.-backed Syrian Democratic Forces (SDF), a Kurdish-Arab alliance, discovered a detention center in northern Syria where ISIS terrorists used some of the “worst, most violent torture tools” on female prisoners,” Ibrahim Al-Mohammed, an anti-ISIS militiaman, told Arab24.

Omar Mazerli, leader of a militia fighting ISIS in northern Syria, added that the jihadist group had been using “various kinds of pills, including sexual stimulation, contraceptives and narcotic pills” to torture detainees at the women’s prison.

Some female victims of ISIS atrocities, particularly members of the Yazidi ethno-religious minority in Iraq, have joined all-women units and formed some of their own to combat and take revenge on the jihadist group.

According to the United Nations High Commission for Refugees, more than 58,000 Iraqis have been displaced by the ongoing offensive to retake Mosul, which began on October 17.

“Many have sought refuge in camps like the one in Khazer, where they may be free of ISIS, but are far from home and haunted by their traumas,” noted NBC News.