[Mediawiki-l] How to block the three last octet of an IP address ?

[Frames Project]

Hello


I only found a way to block the last two octets of an IP address with
nnn.mmm.0.0/16.
Is there a possibility to block the three last octets like :
nnn.0.0.0/8 (which does not work).

(I have a Wiki in french "visited" every day by several chinese people
trying to use it for some political propaganda)

Thanks
François Colonna