As ISIS loses its grip in its stronghold of Mosul, the black-clad jihadist army is plumbing the depths of brutality, taking civilians off the streets of Iraq’s second-largest city and forcing them onto the front lines.

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According to sources within the high ranks of the Yazidi Brigade, which operates under the Kurdish military known as Peshmerga, ISIS - which continues to control the nearby town of Tel Afar – on Friday tricked residents into believing they had “liberated" Kirkuk. The false claim ISIS had seized full control of the oil -rich city came as news of heavy fighting in the region wafted out.

Tel Afar has long held a strong support base for the terrorist outfit, and is considered one of the top places for ISIS recruitment. Much of the ISIS training happens in the Sunni-dominated city, as well as weapon and bomb construction.

"When people from the town heard that Kirkuk had been taken over by ISIS, many came out to the streets to celebrate," a prominent intel source told FoxNews.com on Saturday afternoon from the the Yazidi-controlled front line of Sino, the closest front line to Tel Afar. "With all the families out on the street, ISIS members then executed their scheme and had trucks ready, they filled them with young boys and imported them to the front line Friday night."

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ISIS is said to have used two tanker trucks, two pickup trucks and two armored vehicles to scoop up the minors, aged from 8 to 16.

"ISIS has used all sorts of tactics and human shields many times before," Amer, 43, a lieutenant colonel in the Yazidi Forces, told FoxNews.com. "But this way we just saw last night, this is new."

The boys are apparently being used in three ways on the battle front with Iraqi national forces, Kurdish fighters and coalition troops. They serve as fighters, human shields and suicide bombers. At around 5.30 a.m. Saturday, as the first rays of light rose over the Iraqi desert, a suicide vehicle came toward the Sino front from the Tel Afar line. According to one soldier, who showed FoxNews.com video of the remnants and charred truck, the three inside were minor boys, believed to have been part of the group taken from the Tel Afar streets less than a day earlier.

Two Yazidi soldiers were wounded in the suicide attack and they are bracing for similar attempts in coming days. The two opposing front lines are currently 1.6 miles apart, and the Sino front is about 12 miles from the still deeply rooted ISIS city center of Tel Afar.

By using children as shields, according to one Kurdish official who requested anonymity, ISIS fighters are able to push forward with greater ease, as it puts their opposition on the defensive.

"The Yazidi-Peshmerga tries to snipe behind the shields, but that's very hard," the official noted. "But if the shields open fire first, they have no choice but to shoot back. Otherwise, more and more of our soldiers will get killed."

Col. Marwan Sabri, 35, who oversees the Yazidi Brigade, said the development comes as no surprise.

"ISIS does not follow any international laws, they used banned weapons and children shields," he told FoxNews.com. "This is a group without any morals."

However, the notion of using young boys, who may or may not be radicalized, in the front line fight is one that hits hard for the Yazidi community. According to Sabri, based on their intelligence, Yazidis were likely specifically brainwashed and groomed for the very purpose of being strategically placed on the front lines to fight their own.

Thousands of Yazidis were captured on that apocalyptic Aug. 3, 2014, day when the jihadists invaded their ancestral home on and around Mount Sinjar. Scores of girls and women were kidnapped and sold into sex slavery for the fighters while the boys were forced into jihadist training camps and radicalized to kill their own.

"The use of the children is making things very difficult for us. We don't know who those children are, or if they are one of ours," Amer said, glancing wistfully over at his 18-year-old son, Rayan, also a Yazidi soldier. The men were unflinching amid the sounds of outgoing rockets and mortar rounds blasting from a nearby defense post.

Amer and his family were all living in Germany, known to have a prominent Yazidi diaspora, when their homeland was attacked over two years ago. Almost immediately, he and his wife, along with their six children aged between 6 and 22, returned to help support and protect the embattled region that they left in 2008.

Amer and his two eldest sons joined the Yazidi Brigade, made up of around 8,800 men from the heavily persecuted ethnically Kurdish minority. The brigade was formed last year after Sinjar was overrun by the barbaric Islamist group who declared them "devil worshippers."

His eldest son, Aqeed, was severely injured by an ISIS mortar round three months ago.

"This is a genocide," Amer, who now lives in the decimated once ISIS-occupied city of Sinjar, commonly referred to as Shengal by Yazidis and Kurds. "We have no water, no electricity. But this is our home. We will never leave it again."