Was there a massacre by Sri Lankan forces as they finished off the Tamil Tigers? And did the UN know about it?

Seems so.

The numbers of people killed look to go well beyond the Srebrenica war crime.

Critics of such horrors often miss one of the unspoken points about them. That they are horrible not by some random bad luck, but rather because the perpetrators are making a statement.

See eg the Hama massacre in Syria in 1983. I like to cite this example because it is so vast, and so successful. Up to 30,000 people deliberately massacred by their own rulers who were bent on making a Very Big Point:

Islamist extremism? Not here, thanks.

Not a single diplomatic or other sanction against any of the people responsible for this single horror, as far as I know. Hardly a squeak of media interest.

And in its own terms it was a triumph. Islamist extremists went elsewhere to wreak their havoc.

In short, it set an example.

As did this beheading/crucifiction in Saudi Arabia.

There are plenty of Western precedents for this sort of thing. Hiroshima and Dresden sent strong messages that the Japanese/German WW2 causes were doomed.

In domestic jurisprudence it was only in 1868 that the British government ended public executions of convicted criminals, albeit with one later public execution in Jersey in 1875. And it took until 1878 for the US Supreme Court to observe that drawing and quartering, public dissecting, burning alive and disemboweling would constitute cruel and unusual punishment.

Meanwhile in France, a far more civilised place, public executions (beheadings by guillotine) continued until 1939. See YouTube and this sequence of pictures.

So one part of effecting a huge massacre is not only to stop a conflict but to end it. To send a signal that all further resistance is futile, and that any future conflicts are expected to end in the same way, if not bigger and worse.

Not at all nice. But maybe lots lives are saved in the long run by fewer murders and fewer uprisings and wars? 

Is that what the UN Human Rights Council is saying when its members including Egypt, Cuba, China and India shamefully decide not to criticise Sri Lanka?

Along with a terse message to the West: mind your own business?

Update: Read the excellent comment below by Chris McDowell. I was not precise or clear enough. I did not mean to suggest that there had been a deliberate Srebrenica-like massacre by Sri Lankan forces, although I see that it reads that way – apologies.

Rather I suspect that in finishing off this long job in a military sense they pressed home their advantage in a way unlikely to appeal to Western human rights experts. And because that approach sent a signal of resolve, so much the better.