ATHENS - Militants in Iraq and Syria are holding over 3,000 Yazidi hostages, a Yazidi activist once imprisoned by the Islamic State said Wednesday.

"At this moment there are 3,400 people in detention who are Syrian or Iraqi," Nadia Murad Basee Taha told Greek President Prokopis Pavlopoulos during a visit to Athens.

"I call on you to convey my voice to the European Union because thousands of women and small children continue to be held hostage," said the 21-year-old Taha, a member of one of the Iraqi minorities hardest hit by militant atrocities.

Taha was abducted by IS fighters in August 2014 from her village in Iraq and held for three months, during which time she was used as a sex slave. She managed to escape to Germany and on December 16 told the United Nations Security Council that IS "has made Yazidi women into flesh to be trafficked in."

The Yazidis are neither Muslims nor Arabs and follow a unique faith despised by the Islamic State militant group. The Kurdish-speaking minority is mostly based around Sinjar mountain in northern Iraq.

In 2014, IS militants massacred Yazidis, forced tens of thousands of them to flee, and captured thousands of girls and women as spoils of war. The UN has said the atrocities committed against the small community may amount to genocide.