The UN announced Wednesday that the number of Syrian refugees who have fled the country since the conflict began has jumped since the beginning of the year and has now reached one million.

Half of the refugees were children, most under the age of 11.

Most have fled to or are seeking shelter in Jordan, Lebanon, Turkey, Iraq and Egypt.

"Syria is spiralling towards full-scale disaster," the UN High Commissioner for Refugees Antonio Guterres said in a statement.

"This tragedy has to be stopped," he added.