'Families are on the run again'
Gaza has come under the most intense shelling since the launch of Israel's offensive 13 days ago, with more than 50 people reported killed in one district.
The deaths occurred at Shejaiya, east of Gaza City, Palestinian medics said.
Meanwhile, Hamas is continuing to fire rockets into Israel, with one landing in the city of Ashkelon.
The BBC's Chief International Correspondent Lyse Doucet visited the scene in Shejaiya and said families were fleeing in large numbers.
- From the section Middle East