German author: 'Islamic State brutal and enthusiastic about killing millions'

A German author given unprecedented access to territory controlled by Islamic State (IS), has told the BBC that IS is stronger, more brutal and harder to confront than he had expected.

Juergen Todenhoefer spent 10 days in Mosul, Iraq and Raqqa, Syria where he filmed daily life and spoke to fighters.

He told Caroline Hawley about what he found there.