it is linked to the IDF (check wiki) and it does not have any presence in gaza so based on what have they been giving their number, by the way i can bring tens of research group that give values different than theirs.

most of the 150 Palestinian captured were released so using this number is misleading (on purpose) and they are suspected militant and not militants , check the refference, the same thing happened in lebanon war were israel captured hundreds and after the  war they released all except a handful who were  militants.