More than 300 Islamic State child soldiers - dubbed the "cubs of the caliphate" - have been slaughtered in Mosul after they were sent in to battle by the terrorist group, a human rights group reports.
The Islamic State faces being flushed out of its last stronghold in Iraq as Iraqi and Kurdish forces lay siege to the city.
In a desperate last act, reminiscent of the final days of the Nazis, they have deployed their brigade of child soldiers.
According to the Syrian Observatory for Human Rights hundreds of them have been killed as Iraqi government forces close in - backed by US warplanes and drones.
The UK-based watchdog said: "This will raise the death toll to at least 480 Syrian fighters killed in the ranks of the Islamic State since the start of the battles in the Mosul area, among them more than 300 child soldiers from the 'lion cubs of the caliphate'."
The terrorist group has brainwashed, trained and armed hundreds of children to fight for it.
Sending them in against the pro-government forces echoes the last days of World War 2 when the Nazis deployed its Hitler Youth wing to fight the well-armed Soviet troops.
The slaughter of the child soldiers came as Iraqi and Kurdish forces fought their way to the eastern outskirts of Mosul after a two-week offensive.
But there were no signs yet of a major push inside Mosul itself and bad weather appeared to have limited operations, while forces on other fronts were still some distance from the city.
As well as the killing of child soldiers, human rights groups accused a government-sanctioned tribal Sunni militia of carrying out revenge attacks against men and boys in areas recently recaptured from the militants.
London-based Amnesty International said in a statement on Wednesday that fighters from the Sab'awi tribe, who are taking part in the military operation to retake the city, unlawfully rounded up civilians, beat them with metal rods, gave them electric shocks, placed them in cages and tied some of them to the bonnets of vehicles before parading them through the streets.
The allegations are based on interviews with local officials and eyewitnesses, who said the violations took place in a group of villages located on the south-eastern bank of the Tigris river and under the control of the Sab'wai tribal militia.
Lynn Maalouf, deputy director for research at Amnesty International's Beirut office, describes the violations as "crimes under international law" and adds that Iraqi authorities "must rein in the tribal militia fighters responsible and bring them to justice."
Meanwhile, civilians liberated from the Isis jihadists have spoken about the nightmare of living under the countrol of the group.
"They confiscated my tractor and then threw me in jail for six days. They beat me and when I got out I couldn't do my work anymore," said Yusef Fariq.
The 40-year-old farmer, speaking from his home in Gogjali and surrounded by his mother and two sons, still had the long beard IS militants forced him to grow.
"They were killing us, always asking for money, we couldn't go anywhere. We went through hell," his mother said.
Iraqi troops, meanwhile, said they have killed eight Isis jihadists while carrying out house-to-house clearances in the newly-recaptured neighbourhood of Gogjali in eastern Mosul.
Lieutenant Colonel Muhanad al-Timimi of the Iraqi special forces said on Wednesday that six of the militants were killed inside a tunnel. He says the other two militants attempted to approach the troops and were shot dead. One of the militants was wearing an explosives-laden vest.
Meanwhile, hundreds of civilians streamed out of the adjacent neighbourhood of al-Samah, some holding white flags. All the women wore niqab, a veil that entirely covers the face or only has a small, slit-like opening for the eyes. All of the men were bearded.
The offensive against Mosul marks the culmination of a dramatic turnaround for Iraqi forces. Just over two weeks into a massive offensive to retake the largest city they lost to Isis, Iraqi army and special forces personnel have reached its outskirts for the first time since 2014.