1. Will it be Muslims or any sub sect or Muslim politicians?
No. They are part of loosers.
2. Will it be Hindus or any Hindu politicians?
No. Because they will be at the receiving end(already there are messages in this thread accusing this category) and creats a lot of bad publicity.
3. Pak?
Probably. Through Let or other terror groups to destabilise India.
4. Media?
Probably. You know nothing sells better than bad news for Media. I would not be surprised if some media arranged this to show that they were the first to report, or claim to do some interting 'investigative' journalism.