@Ahsen
Sulphur would probably not damage the engine structurally, as long as you change the oil often. The oil is designed to neutralize acids as well as providing lubrication.
In older engines actually, the ULSD (Ultra Low Sulphur Diesel) actually causes problems with the injection equipment due to insufficient lubrification - yes sulphur lubricates.
IMO, the only thing that will go bang are the catalytic convertors fitted to most new diesel engines. Other than that, all should be ok. As far as the Cetane rating is concerned, probably Pakistan being a small market didn't merit the development of a new diesel map for their engine.
later,
Sami