They want the US and UK forces to stop using the bombs.
Cluster bombs contain loads of mini-bombs, which can scatter to cover an area as large as several football fields.
But up to 30% of the bombs don't explode.
They often remain there for years after the conflict.
Unusual shape
Kids are attracted to them because of their unusual shape and bright colours.
The bombs can be triggered just by someone touching them.
Cluster bombs have been dropped in Iraq, Afghanistan and Laos among other countries.