Lawyers for a 14-year-old Muslim boy arrested after taking a home-made clock to his Texas school say he was publicly mistreated and deserves £9.9 million in compensation.

A law firm representing Ahmed Mohamed sent letters demanding £6.6m from the city of Irving and £3.3m from the Irving Independent School District.

The letters also threaten lawsuits and seek written apologies.

Ahmed took his clock to school in September and a member of staff thought it could be a bomb.

The teenager was arrested but never charged. He was suspended from school.

His family later accepted a foundation's offer to pay for Ahmed's education in Qatar and moved to the Persian Gulf country.

A spokeswoman said the city was reviewing its letter and had no comment.