Iraqis and Syrians who lived under territories held by the Islamic State group say that the extremists have entrenched their rule into a quasi-nation over the past year.

More than 20 people interviewed by The Associated Press describe an extensive bureaucracy run by the group to impose control and spread their radical version of Islamic Shariah law over their territories bridging Iraq and Syria.

Those interviewed provided an array of documents, including copies of "repentance cards" that former government loyalists and police must carry to show they abandoned their "heretical" past.