Many Syrian children have been left without protection, medical care or psychological support
The number of Syrian children in need has more than doubled in the past year to 5.5 million, the United Nations Childrenâ€™s Fund (Unicef) says.
Up to a million are living under siege and in areas that the agency and other humanitarian organizations cannot access, according to a new report.
Children in Syria have lost â€œlives and limbs, along with virtually every aspect of their childhoodâ€, it warns.
UN figures say more than 10,000 have been killed in three years of conflict.
However, the report notes that real number is probably higher.
The statistics presented in Unicefâ€™s report, Under Siege – the devastating impact on children of three years of conflict in Syria, are daunting.
Up to a million children live in areas which are either under siege or very hard for relief agencies to reach, while around three million have had their education completely disrupted.
More than three million been displaced inside Syria – a threefold increase in the space of a year – and 1.2 million – more than half the total number – have become refugees abroad, up from 260,000. Some 425,000 refugees are under five.
In addition, many children have had to start working early and very young girls have been forced to marry for financial reasons. Boys as young as 12 have been recruited to support the fighting.
Around two million children are said to need counseling for trauma.
The Unicef report warns the situation is likely to get worse.
Concerns about the loss of childhood take second place to the need to survive
Unicef has made â€œchild-friendly spacesâ€ in refugee camps to minimise disruption to childrenâ€™s lives
â€œCut off from aid, living in rubble and struggling to find food, many Syrian children have been left without protection, medical care or psychological support, and have little or no access to education,â€ it says.
â€œIn the very worst cases children and pregnant women have been deliberately wounded or killed by snipers.â€
Unicef says it has only been able to raise 8% of the funding it says it needs to do its job properly.
â€œThis war has to end so that children can return to their homes to rebuild their lives in safety with their family and friends. This third devastating year for Syrian children must be the last,â€ said Unicefâ€™s executive director, Anthony Lake.