Syria conflict causing 'staggering' humanitarian crisis

The Middle East faces a "staggering" humanitarian crisis caused by the conflict in Syria, an aid agency says.

With more then 600,000 Syrians having fled the country, the International Rescue Committee is calling on the outside world to step up its response.

It is describing international reaction to the humanitarian crisis as drastically insufficient.

The BBC's Lyse Doucet reports from Lebanon where more than 200,000 Syrians have fled and are currently facing freezing temperatures.