Gas Stations are a problem. Most are owned by Hindus and Sikhs, most of whom are not great practitioners of PC. They carry native land hatreds. It would have some great psychological effect though, simply basing it on the washington dc sniper.
If India is a fair place to observe the mix of Muslims, Hindus and Sikhs, there is no love lost between the groups. The Muslims would be quite pleased if destruction of a gas station did economic damage to either a Hindu or Sikh.
Hindus and Sikhs are also being targetted by radical Islam. I do not see these two groups as a threat per se. The real risk IMHO is that Islamists from the Indian subcontinent (specifically Pakistan) could easily assume a Sikh or Hindu identity as a cover.