The Yazidi Congress Party has released a statement saying that 300 men of their sect being held by Islamic State were massacred on Friday. IS captured up to 40,000 Yazidis last year when their forces swept through Iraq.

BBC:

A statement from the Yazidi Progress Party said 300 captives were killed on Friday in the Tal Afar district near the city.

Iraqi Vice-President Osama al-Nujaifi described the reported deaths as "horrific and barbaric".

Thousands of members of the religious minority group were captured last year.

It is not clear how they were killed, or why this has happened now, says the BBC's Middle East editor Alan Johnston.

Many are reported to have been held in Mosul, the main stronghold of IS after the militants swept through large areas of northern and western Iraq, and eastern Syria in 2014.

Yazidis, whose religion includes elements of several faiths, are considered infidels by IS.

Thousands fled to the Kurdish-controlled region of northern Iraq after IS captured the Yazidi-populated Sinjar district in Nineveh province.

Hundreds of men were killed, while some Yazidi women were held and used as sex slaves.

[...]

The Yazidi Progress Party's statement, quoted by the Kurdish Shafaq News website, condemned the latest incident as a "heinous crime" and called on Iraqi forces to free those still held by IS.

In January, IS released some 200 mainly elderly Yazidis into the hands of Kurdish officials near the city of Kirkuk.

Many of them, held in Mosul, had disabilities or were wounded, though no reason was given by IS for their release.

In recent months, IS has been pushed back from some of the areas it captured, though many Yazidi villages are thought to remain under the militants' control.

You can bet that those 200 Yazidi prisoners released in January were not let go out of compassion. Islamic State doesn't do compassion, or any other elevated human sensibility. Perhaps they didn't want to go to the trouble of burying them when they died. Or perhaps they were released for strategic reasons, such as showing the Sunnis in the area that they weren't all about murder and mayhem - even though they are. Local Sunnis in Anbar province are reportedly upset about the Iraqi government sending in the hated and feared Shia militias to battle IS. Demonstrating what passes for compassion by Islamic State forces might convince some of the Sunnis not to support the Iraqi government's efforts to clear out Anbar of IS fighters.

It hardly matters to the Yazidis. They are helpless in the face of this kind of aggression. All they can do is get out of the way and hope that the fortunes of war turn against their enemies.