An inquiry chaired by UN education envoy Gordon Brown said action is needed to tackle the impact of war on children.
A major inquiry into the protection of children trapped in conflict zones has called for far-reaching and urgent reforms of international law.
There is a "culture of impunity" surrounding attacks on children in many countries including Yemen, Syria, South Sudan and Myanmar, said inquiry chairman and UN Special Envoy for Global Education Gordon Brown.
“It is unconscionable that the world stands by when children are being attacked in their schools and denied access to vital humanitarian aid," he added.
The legal report of the inquiry - supported by Theirworld and Save the Children - urges immediate action to tackle attacks on schools, denial of humanitarian aid, sexual violence against children and other atrocities.
It said there is growing concern over the impact of war on children. Recent attacks include:
The bombing of a school bus in Yemen in August which killed at least 40 children
The suicide bombing in a school in Afghanistan, also in August, which killed around 37 students
Starvation being used as a weapon of war in a host of conflicts including Yemen, where five million children are on the brink of famine
The abduction and gang rape of women and girls as young as eight by government forces and militias in South Sudan between April and July
The inquiry has been headed by leading British barrister Shaheed Fatima QC. Its 500-page report will be launched at an event in London today by Fatima and Brown, alongside former UN High Commissioner for Human Rights Zeid Ra’ad al Hussein.
One major proposal is to give schools the same protection as hospitals under international law. Another is for countries to take positive measures to prevent sexual violence against children.
The report also calls for a clear warning that denying humanitarian access will always be illegal if it might lead to the starvation of civilians.
In the longer term, it recommends the international community consider adopting a comprehensive legal instrument and civil accountability mechanism to govern the protection of children in armed conflict.
“This report sets out an agenda which every government and every organisation working on children affected by conflict should act on, to end the culture of impunity,” said Brown.
Fiona Duggan, Head of Projects at Theirworld, said: "In war zones across the globe today, society’s most vulnerable members are being subjected to unthinkable suffering and too often the world looks the other way.
"The inquiry’s report underscores the urgent need for the international community to build consensus around strengthening the protections for children in conflict, to ensure that every boy and girl has the opportunity to unleash their potential.”
An estimated 350 million children – one child in every six – live amid conflict - an increase of 75% from the 200 million of the early 1990s.
More than 21,000 students and teachers in 41 countries were harmed in attacks on schools and universities around the world over a five-year period, according to the Education Under Attack 2018 report.
Fatima said: “Even where the law provides protection, there is a fundamental lack of compliance and lack of accountability. As a result, and with the increase of intense urban warfare, children are being attacked and killed, in ever greater numbers, and with impunity.”
Kevin Watkins, CEO of Save the Children UK, said: “This is a call to action for governments, international agencies, the UN and non-government organisations. It should be mandatory reading for anyone concerned to see the rule of international law applied to the benefit of the millions of children living in war zones.”