Five years after the violent uprising that brought down Libya's Colonel Muammar Gaddafi, fighters from so-called Islamic State (IS) have established a base in the coastal city of Sirte.

With an estimated 1,500 fighters in the city, they have started to impose their own rule of law, with dress codes for men and women, segregation in school classrooms and the establishment of a religious police.

Punishments inflicted on residents, for crimes ranging from theft or alcohol production to "spying", include imprisonment, amputations, public crucifixions and beheadings. The group has set up its own "police force" and is reported to be carrying out house to house searches and forcing people to attend Islamic re-education classes.