Drive shaft or prop shaft?

As I was driving there was a loud bang and felt like something snapped, after this I car wouldn't move in a gear, when I put the car in gear and release the clutch the prop shaft spins but makes a loud clanging noise ive had a look at the prop shaft and doesn't seem to be bent in any way, the drive shaft however has got about a inch of play when you move it back and forth ( towards the joints ) iam not sure if its the prop shaft has its clanging but still spinning or the drive shaft please help? Cheers