A PhD student accidentally created an explosive chemical used in terror attacks, an investigation has found.

Bristol University confirmed the chemical triacetone triperoxide - better known as TATP - was "unintentionally formed" on Friday, February 3.

The post-graduate student created the highly dangerous substance as a by-product of another experiment, the inquiry discovered.

It is the same chemical used in the 7/7 London bombings, the 2015 Paris terror attacks and the Brussels bombings last year.

Hundreds of staff and students at the university's school of chemistry were evacuated as a result.