The biggest trouble-makers in India are hte Silkhs and Muslims
Been a while since the Sikh extremists struck in a big way IIRC (besides seeing as the current PM is a Sikh anyway, it'd seem an odd time to start all that up again).
Just thinking about this, but the sheer amount of groups that could have done this is depressingly long. The Tamil Tigers have been more active down in Sri Lanka again for one thing... then there's the usual large range of extreme sectarian groups... and the various ethnic seperatists... and those Maoist groups (I dimly recall reading that they've been more active this year. Or was it less active?). O/c it's possible that something has spilled over from Pakistan, Bangladesh or Nepal.
