Counting 3D objects in a stack of images

Hello to all.
I have a stack of images of a CFRP(carbon fiber reinforced polymer) taken by CT.
I should be able to find:
1)single breaks in the fibres
2)clusters (group of neighbouring broken fibres)
3)how many breaks there are in each fibre
4)distance between broken fibres
So far I binarized my image, and I was able to count the broken fibers through 3DObjectCounter and the distance between broken fibres through 3DRoiManager.

I have problems with the other two points because the clusters are considered as single breaks. How can I divide or find these clusters so that ImageJ recognize them?

Thanks in advance.
Best Regards,