The future of 5.5 million Syrian children 'hangs in the balance,' UNICEF warns

A Syrian man holds a crying girl as he gestures following an air strike by government forces on the Sahour neighborhood of the northern Syrian city of Aleppo on March 6, 2014.

The UN said Tuesday the number of children impacted by Syria's war has doubled in the past year to 5.5 million, many of them trapped in besieged areas and beyond reach.

In a report entitled "Under Siege — the devastating impact on children of three years of conflict in Syria," the UN children's agency UNICEF warns that the situation was likely to get worse.

"Cut 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. In the very worst cases children and pregnant women have been deliberately wounded or killed by snipers," the report says.

It said a million children are now trapped in areas of Syria that are under siege or that are hard to reach with humanitarian assistance, while some two million children are in need of psychological support or treatment.

"For Syria's children, the past three years have been the longest of their lives. Must they endure another year of suffering?" UNICEF executive director Anthony Lake says.

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The report focuses on the immense damage caused to children affected by the conflict, including "the accounts of children whose lives have been devastated by the three year old war, and highlights the profound traumas many have experienced."

It warns that "the future of 5.5 million children inside Syria and living as refugees in neighboring countries hangs in the balance as violence, the collapse of health and education services, severe psychological distress and the worsening economic impact on families combine to devastate a generation."

In host countries, 1.2 million Syrian children are now refugees living in camps and overwhelmed host communities, and have limited access to clean water, nutritious food or learning opportunities.

UNICEF estimates that one in 10 refugee child is now working and one in every five registered marriages of Syrian females in Jordan is a child under the age 18.

Jordan is home to more than 500,000 Syrian refugees.

"This 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," said Lake.

Watch Dr. Nancy Snyderman reporting live from a Lebanese hospital that treats Syrian refugees from surrounding camps at noon (via NBC News):