The UN has called for urgent access to fleeing civilians and those trapped in Syria's Eastern Ghouta, which continues to face devastating bombardment by government forces.

It says many of the 50,000 people who have fled in recent days are suffering from potentially fatal illnesses.

Although there was a lull in bombing for a few days, the situation is escalating and an estimated 32 civilians were killed in overnight shelling by government forces. About a dozen of those killed were children who had attempted to shelter from air raids in a school.

The Syrian rescue group the White Helmets says weapons like white phosphorous, which is banned in civilian areas, have again been used.

Al Jazeera's Zeina Khodr reports from neighbouring Lebanon.