When the Islamic State fighters burst into the Iraqi village of Eski Mosul, Sheikh Abdullah Ibrahim knew his wife was in trouble.

Buthaina Ibrahim was an outspoken human rights advocate who had once run for the provincial council in Mosul. The Islamic State fighters demanded she apply for a "repentance card". Under the rule of the extremist group, all former police officers, soldiers and people whose activities are deemed "heretical" must sign the card and carry it with them at all times.

"She said she'd never stoop so low," her husband said.