Harrowing first-hand accounts from Syrian child refugees who say they were subjected to atrocities are contained in a new report by the British charity Save the Children.

Human rights activists say the country's 18-month-old civil war has killed thousands of kids and left many more traumatized.

A report released Tuesday by the U.K. charity compiles 18 first-hand accounts from Syrian refugee children who fled the war-torn country.

In one case, a boy witnessed his family members blown apart when a rocket fell on a funeral procession.

In another, a teenager said he was imprisoned and tortured in his own school, transformed by the regime into a mass detention centre for children.

The six-year-old son of an anti-government activist was abducted, then starved and beaten to death.

Although it did not always specify which side had committed the alleged acts, most — random bombardment of civilian areas, mass abductions by mysterious gunmen — have been linked in the past with the regime's forces or its allied shabiha militias.

'Dogs were eating the dead bodies for two days after the massacre.'—Syrian refugee Hassan, age 14

"Every crime against children must be recorded to send a clear message to all sides in the conflict that these atrocities will not be tolerated," the group said.

Among the accounts in Untold Atrocities: The Stories of Syria's Children: Hassan, a 14-year-old boy now living in a refugee tent camp in Jordan, described what happened when a rocket landed in a funeral procession in his home village.

"Dead bodies along with injured people were scattered on the ground," he said. "I found body parts all over each other. Dogs were eating the dead bodies for two days after the massacre."

Children reportedly used as human shields

Hassan also claimed that government soldiers used children as human shields.

"Another thing they do is to use children to protect themselves. They know we can't shoot our own children, so they put the children in front — so they're a human shield — and march into our villages. It's terrifying for the children. Many of them die," he said, but did not describe any specific incident where this had occurred.

Like most of the accounts in the report, Hassan's account omitted the time and place of the events and other details that could identify him. The group said however that testimonies corroborate other stories gathered by the UN and rights groups, describing the acts as "consistent, recurring and appalling."

These allegations have included the abduction, torture and even killing of children by government forces to punish their parents.

"These are stories that you shouldn't be hearing from children, so we are speaking out on behalf of these children, who have been voiceless until now," said Hedinn Halldorsson, who interviewed some of the children for the report.

"We are calling on the UN to strengthen its montoring and reporting mechanisms because what is needed if those responsible are to be held accountable is documentation of those presumably grave human rights violations going on in Syria," Halldorsson told CBC News.

Teen says children were starved, electrocuted

Khaled, 15, described how a group of men came to his village, arresting him and 100 others, one as young as 12. He was taken to the local school and held there for a week. His captors hanged him from the ceiling by his wrists with his feet off of the ground, stubbed out their cigarettes on his skin, and beat him.

"They took me there to torture me, in the same place I used to go to school to learn. My father was actually the principal there," he said. "When I realized that was where we were going, I was so sad, I wanted to cry."

He said he was given nothing to eat or drink for 48 hours. Others were electrocuted. "I don't think there was a reason — it depended what mood these men were in," he said. "They showed no sympathy, no mercy."

Wael, 16, was also caught up in a mass detention. He said the captors were especially cruel to a 6-year-old boy, Alaa, because his father was wanted by the regime of President Bashar Assad. Alaa was tortured and denied food and water for three days.

"I watched him die. He only survived for three days and then he simply died," Wael said. "He was terrified all the time. They treated his body as though he was a dog."

"I don't think I'll ever be OK again," Wael said.

Syria's uprising began in March 2011 and has since become a civil war. Activists estimate some 30,000 people have been killed, including close to 2,000 children.

In the most recent violence, Syrian warplanes bombed two buildings in the embattled northern city of Aleppo on Monday, killing at least five people including three children from the same family, activists said. They say the aim behind such strikes on residential areas is to terrify people and turn them against the rebels.

Syria rarely responds to allegations of rights abuses. Its embassy in Amman could not be reached for comment. The regime blames the country's troubles on "terrorists," its term for the rebels, backed by a foreign conspiracy.

In its recommendations, Save the Children urged the United Nations to increase its presence on the ground to document violations. The Security Council decided last month to end a 300-member UN military observer mission that was sent to monitor a ceasefire that never took hold, replacing it with a small liaison office that will support any future peace moves.

The group said many children will need specialist care to recover from what they have seen and experienced. Save the Children said it is providing support to children who are showing signs of distress, including nightmares and harming themselves.