The number of children killed in the horrific conflict is believed to have reached up to 55,000 since the war began – more than the number of Britons killed in The Blitz.
The war rolls into its sixth year tomorrow, rivalling the length of the European battlefield of the Second World War, and taking the lives of almost half a million people.
Human rights campaigners have claimed Britain is “complicit” in the world’s failure to intervene and end the conflict.
CEO of War Child UK Rob Williams claims while Britain has been a “generous donor” in the region, the UK needs to do more to bring the war to an end.
Mr Williams said: “No child has ever started a war, yet Syria’s children are the innocent victims in this conflict, caught up in violence that has engulfed their lives for six years now.
“The war in Syria is a war on children – schools and hospitals are being targeted, boys and girls are being killed by the hour, while the international community just watches.”
While the estimated 55,000 children killed in the conflict would be enough to fill the seats of Manchester City’s Etihad stadium to capacity, some 400,000 are believed to still be facing sieges while another 2.3 million have been forced to flee their home country.
Mr Williams added: “The sheer scale of this tragedy and the lack of action on behalf of the international community is a betrayal of Syria’s children.
“Enough is enough – the international community must work together to immediately stop attacks on children and end this horrific conflict.”
The estimated 55,000 children killed make up just 13 per cent of the 400,000 civilians believed to have lost their lives as the war rages through their streets.
British actress Carey Mulligan, star of The Great Gatsby and Suffragette, has called on world governments to “step up” and help “stop the fighting”.
She added: “Throughout this horrendous war children have suffered on an astronomical scale and continue to do so.
“They are dying in Syria and being neglected by the world in refugee camps.
“These children have done nothing to deserve their situation, and are innocent victims in a war they did nothing to cause.
“It’s time for the rest of the world to step up and do everything they can to stop the fighting and help Syria’s children build a better future.”
It comes as the Syrian war rages on between the government troops of Bashar al-Assad and rebel forces attempting to oust the dictator.
The brutal field of war was complicated even further when, 3 years into the war, vile ISIS jihadis began to seize cities in the region – displacing even more people and feeding the growing refugee crisis.