This is the 155mm Field Howitzer 77, one of the deadliest artillery pieces in the world. It was manufactured by Swedish weapons company Bofors in the 80s, but this model is new—a complete mechanical and electronics overhaul over the old one.
The Indian Army is retrofitting 410 of them for deployment in 2013. Watch them demonstrating it to the public in this hilarious video above; it makes you think the whole thing is a joke...until the terrifying explosion at the end.
To be honest, I don't know why they need such a deadly weapon. Looking at it, they can probably kill their enemies by dancing like in front of them, or just by mailing them this GIF, below. [Thanks Michael!]