Fleeing Gaza families take shelter at UN school

Israel has warned residents in northern Gaza to evacuate as it prepares to launch fresh air strikes.

At least 159 Palestinians have died as a result of Israel's offensive in the area in recent days, according to health officials in Gaza.

Some of those who have fled their homes have travelled to a school run by the UN which has been set up as a temporary shelter.

Yolande Knell reports.