Non-state armed groups have used children who appeared as young as 10 to participate in Syria’s devastating civil war, Human Rights Watch (HRW) said in a report released Monday. Boys joined the armed groups for various reasons — and were sometimes lured with the promise of education — but many ended up being used for suicide missions and other dangerous tasks.

The report is based on interviews with 25 former or current child soldiers who talked to the HRW researchers from their homes in refugee camps, clinics and public gathering places. The total number of child soldiers fighting in the Syrian civil war is not known, but a local monitoring group, the Violations Documenting Center, found that 194 “non-civilian” male children have been killed since the beginning of the conflict, which is now in its fourth year. Recruiting child soldiers, under age 15, in both combat and support roles is considered a war crime that can be tried by the International Criminal Court.

A boy called “Saleh,” 17, told HRW he fought with the Free Syrian Army (FSA) — the Western-backed opposition group fighting against Syrian President Bashar al-Assad — at 15 after he was detained and tortured by government security forces. He later joined two other armed groups. (All children's names are pseudonyms given by the researchers.)

“I thought of leaving [the fighting] a lot,” he said. “I lost my studies, I lost my future, I lost everything.”

Another boy, going by “Majed,” 16, said that Jabhat al-Nusra — a radical Islamist anti-Assad group — in Daraa promised him free schooling at a local mosque that included military training, Quran study and target practice. He said that commanders encouraged children to sign up for suicide attacks, according to the report.

“Sometimes fighters volunteered, and sometimes [commanders] said, ‘Allah chose you.’”

Priyanka Motaparthy, the report’s author, called the use of child soldiers the war’s “blind spot” and warned about the dangers of accepting children’s participation in war as a fact made inevitable by extreme circumstances or local interpretations of adulthood.

“So many people will tell you, ‘you’re considered a man as of the age of 16,’” but children are not, she told Al Jazeera.

Children were reported to have served for groups including the FSA, Jabhat al-Nusra, the Islamic State of Iraq and the Levant (ISIL) and Kurdish forces in northern Syria. The researchers found groups often neglected to check children’s real ages and failed to turn them away when suspecting they weren't adults. Some FSA commanders said their units did not accept children as a matter of official policy, but would ultimately accept anyone eager to fight.

“16, 17 is not young. [If we don’t take him,] he’ll go fight on his own,” Abu Rida, leader of the Saif Allah al-Maslool brigade, an FSA group in Daraa, told HRW.

Children’s reasons for joining varied, but contrary to the experience of child soldiers in places like the Democratic Republic of Congo or countries where children were often forced to join rebel groups, the Syrian child soldiers interviewed by HRW all said they had volunteered.

Some who had been arrested or tortured reported that disillusionment with the regime had kindled their political enthusiasm and a sense of duty. Others said they followed friends or relatives, or joined because of the promise of education in areas where the government had stopped providing classes.

“But the problem is that they are extremely vulnerable and young but they don’t necessarily have a sense of what they’re getting in to,” Motaparthy said.

“Children under that age, their brains are not fully developed, they’re not able to understand long-term consequences of action. Some of the children I talked to said, 'I didn’t understand it would take this long,' they thought they signed up for three months, not for three years.”

Since the beginning of the conflict, the levels of violence have steadily increased.

“Back in 2012 the worst weapon for a kid was a assault rifle,” she said. “Now it’s mounted machine guns.”

Some commanders also reportedly preferred younger children to execute combat mission because they were braver. One doctor described treating a boy between 10 and 12 years old whose job it was to whip prisoners held in an ISIL detention facility, according to the report.

All children interviewed by HRW are boys. Except for the Kurdish forces in northern Syria, no other armed groups had recruited girls to assist with combat operations — an observation that follows the rights group’s earlier findings on ISIL’s and other groups' increased restrictions of the movement of women and girls in accordance with their extremist interpretation of Islamic law.

HRW called on the United Nations’ Security Council to refer the crimes to the International Criminal Court. It also urged the Syrian government to stop providing aid to groups using child soldiers in their operations.

“Anyone providing funding for sending children to war could be complicit in war crimes,” Motaparthy said.