Yazidi refugees in Iraq
Yazidi refugees in IraqReuters

Several hundred Yazidi captives have been killed in Iraq by Islamic State (ISIS) terrorists west of Mosul, Yazidi and Iraqi officials said Saturday, according to the 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, the BBC noted. Many are reported to have been held in Mosul, the main stronghold of ISIS after the terrorists 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 ISIS captured the Yazidi-populated Sinjar district in Nineveh province.

ISIS, which has declared a caliphate in parts of Iraq and Syria it captured, forced tens of thousands of Yazidis and Christians to flee their homes or face certain death. Members of the group have also taken hundreds of Yazidi women captive and have been holding them in schools in Mosul.

In January, ISIS 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 ISIS for their release.

The UN has said the ISIS campaign of killings, abductions and rape against Yazidis may amount to genocide - but the International Criminal Court (ICC) has made clear that it would not prosecute the group.