09/03/2013 13:54 EDT | Updated 11/03/2013 05:12 EST

2 million refugees have fled Syria, says UN

More than 2 million refugees have fled Syria into neighbouring countries, while another 4.25 million are displaced inside the country, according to the United Nations refugee agency UNHCR. More than half of the refugees are children.

The UN has characterized the refugee crisis as one of the greatest tragedies of this century.

Peter Kessler, spokesman for the United Nations High Commissioner for Refugees, told CBC News from Lebanon that people living in sprawling refugee camps — some the size of small North American cities, with up to 120,000 inhabitants — are growing anxious and fearful by the day.

"We're certainly seeing a sense of extreme abandonment, of insecurity," said Kessler, adding that many of the refugees are traumatized children who have not been able to attend school in over two years.