International human rights lawyer Amal Clooney has called upon the Iraqi government to allow a UN investigation into the treatment of Yazidis by the so-called Islamic State (IS), reports Reuters.

A year ago, the UK Parliament joined US Secretary of State John Kerry, the US House of Representatives, the EU Parliament and the Parliamentary Assembly of the Council of Europe in describing the actions of IS (or Da’esh) as genocide.

In June last year, UN experts reported that IS militants seek to destroy the Yazidi group, whose beliefs combine elements of several ancient Middle Eastern religions, through murder, sexual slavery, gang rape, torture and humiliation that amounts to genocide.

Some religious leaders and other sources, including Vienna-based legal counsel Ewelina Ochab, believe that the campaign of genocide also extends to Christians.

Prior to the US-led invasion of Iraq in 2003, there were 1.4 million Christians in the country. Today there are thought to be fewer than 200,000. World Watch Monitor reported in May last year that Christianity “could disappear” from Iraq and Syria within five years, according to Catholic sources.

Britain is drafting a UN Security Council resolution to establish an investigation, but Clooney said the Iraqi government needs to send a letter formally requesting the inquiry before the council can vote.

Clooney, who represents Yazidi victims of IS, told reporters, “We do want to see an investigation take place with the cooperation of the Iraqi authorities, but ultimately if that support is not forthcoming in terms of real action, then the UN has to think of other ways in which to achieve accountability.”

Since 2014, when IS took control of parts of Iraq, Yazidis and Christians have been under severe, and often violent, pressure with many Christians being given four options: to leave, convert to Islam, pay the jiyza (tax), or be killed. A report last October highlighted this accelerated targeting of “disproportionately suffering” Middle East Christians.