A nine-year-old girl is pregnant after being kidnapped and raped by Islamic State militants, according to an aid worker.

The girl was one of more than 200 Yazidi women, children and elderly who were released near Kirkuk in northern Iraq after being kidnapped at gunpoint last June.

"The abuse she has suffered left her mentally and physically traumatised," Canadian-based aid worker Yousif Daoud, who recently returned from the region, told The Toronto Star .

"This girl is so young she could die if she delivers a baby. Even caesarean section is dangerous."

ISIL have released pictures and video of them destroying ancient historical artifacts and sites. (Supplied) (Supplied)

Mr Daoud said the girl, a member of the persecuted Yazidi Christian minority, was found in "very bad shape" and had been sexually abused by 10 men.

"Most of them were frontline fighters or suicide bombers who are given girls as a reward," he said.

The girl has since been flown out of Iraq by a Kurdish aid agency and is receiving treatment in Germany.