Disturbing videos have emerged on social media that appear to show U.S.-backed Iraqi forces torturing children as they advance towards Mosul, the last major stronghold of the Islamic State (ISIS/ISIL) in Iraq.

Breitbart News recently learned from an American defense official that Iraqi forces receiving U.S. assistance during the ongoing operation to liberate Sunni-majority Mosul from ISIS were vetted for links to terrorism and affiliation with state-sponsor of terrorism Shiite Iran prior to the start of the offensive.

The Iraqi troops and their allies – namely Kurdish forces, Iran-allied Shiite militias, and Sunni tribesmen – are being advised by American forces on the ground and backed by U.S.-led airstrikes called in by U.S. forces.

The Daily Mail notes:

Harrowing videos have emerged which appear to show children in Mosul being tortured and beaten with hammers by Iraqi soldiers and militia. The civilians, some of whom look as young as eight, were assaulted while being interrogated by the Western-backed troops over whether they were loyal to ISIS, reports claim.

The news outlet acknowledges that it has been unable to independently verify the authenticity of the videos, noting that most of the content is “too graphic” to show.

It is unclear if the troops shown in the footage are Iraqi Security Forces (ISF), Shiite militiamen, or Sunni tribesmen, all of whom are participating in the Mosul operation.

One of the videos shows a young boy screaming in pain while he is interrogated by armed men in military uniform believed to be from the Iraqi army:

Referring to himself as Ihab Muhammad, the young man reveals that he recently escaped from Iraq’s second largest city Mosul, reports Middle East Monitor.

The boy is reportedly asked if he or any of his family members are linked to ISIS and is then beaten by the soldiers who apparently do not like his answer.

Shut up “or else I will kill you,” one of the soldiers tells the young man as he screams in pain, notes the Middle East Monitor.

The Daily Mail adds:

One horrifying video shows a young man being hit on the knee with a hammer before a slab of concrete was thrown onto his head in front of a crowd of soldiers. The boy could be heard yelling “no no” when he was brutally kneecapped. After the attack, the boy was told to “stand up man.”

Other footage, posted to Twitter on Tuesday, shows a boy being struck over the head with an automatic weapon while he sits handcuffed in the back of a truck. The blood-covered youth can be heard screaming in agony as the troops repeatedly hit him – while others gathered round and filmed the attack on their phones.

Last week, human rights group Amnesty International warned that civilians fleeing Iraq’s second largest city Mosul would likely suffer death and torture in “brutal revenge attacks” at the hands of Shiite militias sanctioned by the Shiite-led Iraqi government.

According to the American military, the U.S. is only backing the Sunni component of the predominantly Shiite militia umbrella group known as Popular Mobilization Units (PMU) or Popular Mobilization Forces (PMF), which also includes Sunni tribesman.

PMU fighters, many of them backed by Iran, are currently participating in the Mosul operation at the behest of the Iraqi government.

To retake Mosul from ISIS, the Shiite-led Iraqi government has assembled a force of up to 30,000 ISF, Kurdish Peshmerga troops, Sunni Arab tribesman, and Shiite militias, including those backed by Iran.

The participation of thousands of Shiite militias prompted concern that they will carry out atrocities against the majority Sunni population in Mosul in retaliation for ISIS’ barbaric actions, as they have done in the past, namely during the U.S.-backed Fallujah offensive.

According to the Washington, D.C.-based Institute for the Study of War, Iran’s Shiite terror proxy Hezbollah and other Shiite militiamen with violent records of sectarian killings and histories of murdering American troops are taking part in the offensive.

Last week, the New Yorker suggested that Hezbollah and other dangerous Shiite militia members may have donned Iraqi military uniforms to participate in the Mosul offensive.

Nevertheless, a U.S. defense official told Breitbart News that it did not have any information on Hezbollah fighting alongside U.S.-backed Iraqi troops near Mosul.