A BBC undercover report has revealed the extent to which the so-called Islamic State use social media to encourage people to travel to Iraq and Syria.

The tactics have been compared to online grooming.

By the end of 2015 it is thought more than 700 people had left the UK to join Islamic State.

You can watch the full report on BBC1 Inside Out on Monday at 1930 in Yorkshire and Lincolnshire and afterwards on the BBC Iplayer and explore the issue of radicalisation in a News Guide.