> Recently, there was almost a riot in our university because of Afghan students (though Indians were also involved!)
Well, lay the blame quickly! Good start. Make the Indian involvement seem almost incidental.
> A student's car brushed slightly against an Afghan student
Ah, cars don't really brush slightly, now do they? That reads more like "he hit the student with a car" to me. Though perhaps you believe in the stereotype of the exceedingly careful Indian driver, especially the youths... ;)
> and some 10 of them beat him up.
What's "some 10"? Is that an accurate estimate? I'll take your word for it.
> Then Afghans were beaten
Interesting move to the passive voice! Compare "10 of them beat him up" to "Afghans were beaten". It almost seems like it was simply circumstance. I think Indian were more than "also involved", don't you? They beat up the Afghans after hitting one of them with a car.
> In reply, they were planning to beat down every Indian student in our hostel.
Did they put this out on Twitter or Facebook? I think you mean, "someone spread a rumour that they were planning to beat down ever Indian".
> Situation went ugly when Indian students threw stones at police.
And again, more "involvement".
> The point is that Afghan students are not that, well, behaved and cause lots of problems.
Perhaps, but your story doesn't support that.
Your tale sounds like a kid trying desperately not to lie, but bending the truth just about as far as possible to make it seem that "he started it and it's all his fault" :)