Image copyright EPA Image caption Amal Clooney addressed members of the United Nations

Lawyer Amal Clooney has urged the UN to act against so-called Islamic State by backing a UK-led investigation into the group's atrocities in Iraq.

Speaking at the UN, Mrs Clooney said IS had declared it will "destroy" the country's Yazidi ethnic group through murder, rape and forced conversions.

The British-Lebanese human rights lawyer said IS was also attacking Christians, and Shia and Sunni Muslims.

Mrs Clooney, who is based in London, accused the UN of "inaction".

She said: "The UN was created as the world's way of saying 'never again' to the genocide perpetrated by the Nazis.

"And yet here we are, 70 years later, discussing the UN's inaction in the face of a genocide that we all know about, and that is ongoing."

The UK is drafting a Security Council resolution to establish a UN investigation, but Mrs Clooney said the Iraqi government needs to send a letter formally requesting the inquiry before the 15-member council can vote.

Media playback is unsupported on your device Media caption Amal Clooney said the Yazidi testimony was "harrowing"

Mrs Clooney called for mass graves to be preserved and exhumed, and witness evidence to be recorded, even if it was not supported by Iraqi Prime Minister Haider al-Abadi, who was present at the UN meeting.

Mrs Clooney said the organisation should press ahead regardless.

She ended her speech to the UN by saying: "Don't let this be another Rwanda, where you regret doing too little, too late. Don't let Isis [Islamic State] get away with genocide."

Who are the Yazidis?

Media playback is unsupported on your device Media caption Yazidis revere the Bible and Koran - but much of their tradition is oral

Religious sect found in northern Iraq, Syria and the Caucasus

Religion incorporates elements of many faiths, including Zoroastrianism

Principal divine figure, Malak Taus (Peacock Angel), is the supreme angel of the seven angels who ruled the universe after it was created by God

Many Muslims and other groups incorrectly view Yazidis as devil worshippers

There are estimated to be about 500,000 Yazidis worldwide, most living in Iraq's Nineveh plains

In August 2007 jihadists attacked Yazidi villages in Nineveh, killing between 400 and 700 people

Who, What, Why: Who are the Yazidis?

Mrs Clooney, a barrister at Doughty Street Chambers, appeared at the UN in New York to represent victims including Yazidi genocide survivor Nadia Murad.

Ms Murad told UN members: "I can't understand why you are letting IS get away with it."

Last year, the UN accused Islamic State for the first time of committing genocide against Yazidis in Iraq and Syria.

A report said IS had subjected captured Yazidis to the "most horrific of atrocities", killing or enslaving thousands.

At least 3,200 Yazidis were being held by IS, the report stated.