France presses at U.N. for Islamic State to face world court

The United Nations has also said the group, which last year seized swathes of territory in Iraq and Syria, may have committed genocide against the Yazidi minority in Iraq.

Iraq and Syria are not members of The Hague-based international court, which means its prosecutor is unable to open an investigation unless a referral is made by the 15-member Security Council.

French Foreign Minister Laurent Fabius told a council meeting on ethnic and religious-based attacks in the Middle East that Islamic State militants must be prosecuted and that "it is essential that the Security Council refer the matter to the International Criminal Court."

Bill Schabas, professor of law at Britain's Middlesex University, said "there's no rule that says it's impossible" to refer a group to the court even if it operates in countries that are not members.

He said it would be first for the prosecutor and then the judges to decide if an Islamic State referral was legitimate.

"If the court did get involved, it could, if it saw fit, then interpret the referral in its own way, expanding it to cover Syria and Iraq," Schabas said.

France led a bid by council members last May to refer the civil war in Syria, now in its fifth year, to the ICC for possible prosecution of war crimes and crimes against humanity.

But it was vetoed by Syrian ally Russia, backed by China. The remaining 13 council members voted in favor. Fabius said on Friday that France would again try to refer Syria.

Air strikes by a U.S.-led alliance have targeted Islamic State strongholds in northern Syria and Iraq for the past six months.

The International Criminal Court has previously dealt with the referral of a group, rather than a situation in a country, for possible prosecution. In 2003, ICC member Uganda referred the situation concerning the Lord's Resistance Army (LRA).

The LRA rose up against the government in northern Uganda under the leadership of Joseph Kony in the late 1980s. The group has been accused of abducting children to serve as fighters and sex slaves. Kony and four other senior commanders were indicted by the ICC for war crimes and crimes against humanity in 2005. (Additional reporting by Thomas Escritt in Amsterdam; Editing by Grant McCool)