Baghdad, Iraq - Evan al-Jaf was walking to her aunt's house in the Jadriya neighbourhood of Baghdad last month with three friends when she realised that a group of men had followed them from Tahrir Square, the city's main anti-government protest site.

The 19-year-old, a volunteer field medic at the square and a first-year law student, said the men suddenly grabbed and blindfolded her, before taking her to an unknown location.

"They came for me," she told Al Jazeera, adding that her friends were not targeted. "They told me they were from the anti-terrorist forces, but I'm sure they were Hashd al-Shabi," she said, referring to the umbrella of Iran-backed militias also known as the Popular Mobilisation Forces (PMF).

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Al-Jaf, who has leukaemia, said she was tortured by four men.

"They beat me up until I started throwing up blood, and electrocuted me," she said, pulling her shirt up to reveal burn marks on her back. "They tied my left hand to my right leg and my right hand to my left leg."

"They wrote on a whiteboard things that they wanted to film me saying that weren't true, such as 'Tahrir Square is an immoral lawless place where rape is rampant,'" she said. "I didn't want to read it out, but they put a gun to my head. They saw that I'm a Christian and accused me of being an agent for the Kurdish intelligence."

Al-Jaf says she was electrocuted and beaten while in detention [Linah Alsaafin/ Al Jazeera ]

After two days in captivity, al-Jaf was released overnight on an expressway in the rural district of Taji, north of Baghdad.

"I was back at Tahrir Square four hours later, and went straight to a doctor I know at one of the medical tents, crying. I told him everything," she said.

"I saw one of the men who kidnapped me the following day. He was wearing olive fatigues and sunglasses, and nodded at me," she added.

'Unrestrained militias'

Activists have blamed unidentified armed groups, that are not part of the government security forces but are affiliated with the PMF, for attacks against anti-government protesters.

In December, the UN said in a report in that "groups referred to as 'militia', 'unknown third parties', 'armed entities', 'outlaws' and 'spoilers' are responsible for the deliberate killings and abductions of demonstrators."

"These acts contribute to a climate of anger and fear," it added.

The PMF was formed in 2014 after a call from Iraq's most influential Shia leader, Ayatollah Ali al-Sistani, to take on the ISIL (ISIS) after it had conquered more than a third of Iraqi territory. In 2016, most of the PMF militias were incorporated into the state's security apparatus, but critics say that some militias operate independently of the government. The militias have also become a powerful force in Iraqi politics, with strong representation in the Iraqi Parliament.

Wathiq al-Freiji, one of the protest organisers in Baghdad, told Al Jazeera that Iraq has a security problem mainly because of "unrestrained militias".

"Weapons should be under the control of and limited to the government," he said. "These militias are tied to political parties and are not merely associated with but control the government."

Iraq has a security problem mainly because of 'unrestrained militias', according to p rotest organiser Wathiq al-Freiji [Courtesy of Wathiq al-Freiji]

"They enjoy important roles in the security, intelligence, interior and defence branches," the 37-year-old said. "We are in no doubt that the crackdown on protesters is a systematic, organised joint process by these militias and political blocs who both want to safeguard their interests."

According to the Iraqi High Commission for Human Rights (IHCHR), there are currently 64 missing activists who have been kidnapped by unknown groups since anti-government demonstrations began on October 1.

Dr Ali al-Bayati, who works with IHCHR, said that the Iraqi government has a responsibility to "expose the perpetrators and those responsible for the kidnappings in the security forces' area of control".

"Iraq is part of the agreement to protect people from enforced disappearance since 2009, so it has to adhere to the terms of the agreement and conduct professional and judicial investigations on the issue and hold the perpetrators accountable," he said.

"Otherwise, failure to act will open the door for international bodies and UN committees to intervene."

Electrocution and beatings

Protesters have accused various security forces, some who are under the umbrella of the interior ministry, and others not linked to government ministries, of using heavy-handed tactics against them, such as arrest and torture, since protests began.

Yaser al-Jaber, a 23-year-old field medic at Tahrir Square, was alone when he was arrested on November 6 while walking near the Central Bank of Iraq building in Baghdad.

Yaser al-Jaber says he was detained and tortured at the old Muthanna airport prison [Linah Alsaafin/ Al Jazeera ]

"I spent 78 days in detention at the old Muthanna airport prison in west Baghdad," he told Al Jazeera.

According to al-Jaber, he was tortured by members of the joint military-police Baghdad Operations Command (BOC).

"They would beat me up trying to get me to confess if I set fire to a building, for example, or burned tyres, or if I set up roadblocks," he said. "They accused me of attacking their officers. They would tie wires around my hands, legs and genitals and give me electricity shots."

Al Jazeera contacted the BOC for comment but did not receive a response prior to publication.

Government crackdown

A protester suffers from tear gas inhalation at Baghdad's Tahrir Square [Emma Francis/Al Jazeera]

Protesters and rights groups have also accused government security forces of resorting to violence, including firing live ammunition, tear gas and rubber bullets in an attempt to break up demonstrators.

On Monday, Iraqi state TV announced that the death toll since the protests began had reached 556, including 13 members of the security forces. The IHCHR put the number as slightly lower at 536.

"We consider blocking the roads our constitutional right and a form of pressure to get our demands answered, whereas the riot police see it as vandalism," al-Freiji, the protest organiser, said.

A government committee found in October that security forces used excessive force to quell protests.