ISIS threatens Britain's little prince: We'll attack him while he's at school.

Extremists allegedly posted the message along with a photo of the future king entering his Battersea school in telegram, an encrypted message application.

The message included Thomas' Battersea School address, and they wrote that school starts early.

Residents living near Prince George's school, as well as parents of other students, had raised concerns about the security of Thomas' Battersea and their children's lives.

An investigation by the Daily Star revealed messages in the Telegraph, which British spies are now constantly monitoring to prevent possible ISIS attacks.

Just four days before George started school, a woman has filmed herself walking through uncontrolled school corridors, expressing surprise over the lack of security that existed in that school. Meanwhile in September, a woman was arrested in school after trying to enter twice within 24 hours. The private school is working with Matt's Kingdom Rights Protection Committee on all security issues.