Even if the military targets killed by these devices are not considered war crimes, there were several civilians killed and those deaths should be considered war crimes.

The problem with using a weapon like this is that you can't possibly know who is nearby at the detonation time. To me this seems similar to butterfly mines which have been internationally banned for 2 major reasons:

• they can end up outside the military operation area - they're light enough that they can be blown off-course while falling, and will float downstream if they land in water
• children pick them up because they look like plastic toys

It seems like the same logic should apply - this weapon is not discriminating enough and is therefore not a legitimate military option.