The 11-year-old's singed hair is matted with dirt and blood.

Flesh peels from the burns that cover his body, hands and face. His expression is blank, frozen with shock, but the brown eyes that stare up from above his mangled cheeks and cracked lips are wide with fear.

He tries to lie perfectly still under the covers of the bed in the makeshift clinic, but, despite his efforts, his small body quivers and trembles uncontrollably.

Ahmed is the collateral damage of the Syrian war; one of hundreds of thousands of civilians, more than half of them children, who have been maimed or made homeless in almost three years of conflict.

The Russia-United States brokered deal for the Syrian regime to give up its chemical weapons has been heralded as the most significant diplomatic breakthrough in the conflict.

But it does little to address the use of conventional weaponry - air strikes, Scud missiles and artillery - that has already taken the death toll to more than 100,000.

As United Nations inspectors travelled to Syria to act on the chemical weapons disarmament deal, the Daily Telegraph witnessed first hand the aftermath of a car bomb - now a daily reality - in the Damascus countryside that killed at least 37 people and wounded dozens more, including Ahmed.

The bomb had detonated outside the front of a mosque in the rebel-held town of Rankous, 24km north of the capital, as residents left the area after prayers. The explosion sent up a huge ball of debris and flame, collapsing the front entrance of the mosque on to the worshippers.

There was no clear reason for the attack, or even knowledge of the perpetrator. Some blamed the Syrian regime. Others blamed Hizbollah, the Lebanese militia fighting in Syria for President Bashar al-Assad.

But in a field hospital in the neighbouring rebel-held village of Yabroud, where most of the casualties were taken, little thought was given to the motive.

The Daily Telegraph watched as the casualties spilled out of the already makeshift wards. Doctors lay down tatty mattresses in an empty building next door to deal with the overflow of men and boys with horrific burns or bleeding profusely from shrapnel wounds.

Ahmed was treated in the main building, volunteer doctors cleaning and bandaging his hands, which had been reduced to skinless stubs of clotted blood and grime. The boy looked on mutely.

Earlier that day, Ahmed had decided to go to Rankous with his father and two brothers, who are all apple farmers, to help them sell the family's produce.

"Ahmed usually goes to school, but today is off so he wanted to come with us to have some fun," said his brother, 22, who lay in a nearby bed but was too frightened to give his name.

Ahmed's father, Mohammed, 57, who was also wounded in the blast, said: "We had stopped our work to pray in the mosque. I was inside finishing a last prayer, but my children were outside when the bomb exploded.

"I started searching for them. I was walking through the dead bodies praying that my children were not among them. I found Ahmed lying outside on the ground, completely burned."

Tears streaked down the father's face as he talked. "He is always such a happy boy. He is good in school, he has nothing to do with this war. We were just trying to live our lives."

The fighting in Syria has now reached almost every city, town and village in the country. It is producing a generation of war children; of girls and boys who have been maimed, displaced, psychologically traumatised or at least deprived of years of schooling.

In districts where civilians are living under siege, such as Eastern Ghouta in Damascus, food supplies are often limited, causing chronic child malnutrition and dehydration.

The Daily Telegraph visited a school in Yabroud that had been turned into a refuge for families that had fled the fighting elsewhere. Mattresses were laid out on the floors of the classrooms that had been cleared of chairs and tables. The ledges of the blackboard were used to store tins of food supplied by a local humanitarian aid group.

Almost all of the more than 100 refugees living there were widows or children whose fathers had either been killed or disappeared.

One mother, who asked not to be named for fear of recrimination by the Syrian regime, spoke of her family's experience fleeing the town of Qusayr in Homs province after it was attacked by Hizbollah and the Syrian regime.

As she spoke her 5-year-old daughter Mariam sat repeating "whoosh, boom" over and over, in imitation of a fighter jet launching an air strike.

As the rebel front lines in Qusayr collapsed and her father, a fighter in the rebel Free Syrian Army, was killed, the family had been forced to live in an empty water pipe underground for three months, surviving on a mixture of rice, grass and tree leaves.

"The town was besieged. We had no supplies coming from outside, so everything in the markets finished," said Mariam's mother. "We ate rice and when that finished we used leaves from trees and grass."

Dozens of other families lived underground with them, she said: "We had 5m of the pipe for us. Each family made a hole in their part of the pipe and built steps to escape. We put a mirror by the hole outside so that it would reflect the light into the pipe. We lived only to hear sounds of the planes, waiting for when they would bomb."

In recent months Mariam, an energetic girl with thick brown hair, had been uncontrollable and aggressive, her mother said.

"She refers to herself in the masculine, as if she is a boy," she said. "She punches the other children."

Mariam's brother, Mohammed, 6, sat beside her drawing pictures of a tank, a helicopter, and an MiG plane.