The U.N. Secretary-General is condemning another attack on a Gaza school as a "moral outrage and a criminal act".

It's the second attack on refugees taking shelter from the fighting between Israel and Hamas in four days.

Just days ago, Israel was accused of shelling a similar building.

Ban Ki-moon's demanded those responsible for the 10 deaths be held accountable.

Our reporter Shona Murray is on the ground in Gaza right now: