Three terror arrests have been made across the UK by police believed to be investigating a neo-Nazi group that has posted an online threat against the Duke of Sussex.

A 17-year-old boy from London, an 18-year-old man from Portsmouth and a 21-year-old man from Bath were arrested on Thursday, the North East Counter Terrorism Unit said.

The force said the pre-planned operation was part of an ongoing investigation into "extreme right-wing activity".

It is understood a neo-Nazi group named the Sonnenkrieg Division is included in this investigation.

One propaganda image shows a picture of Harry with a pistol pointed at his head and the words "see ya later race traitor", according to various reports.

Other swastika-branded images show praise for mass murderer Anders Breivik and an affection for the noose.

Detectives were continuing to look for evidence in four properties in Leeds, Bath, London and Portsmouth.

Two suspects were being questioned in London police stations, the other in Bath.

The oldest was arrested on suspicion of possessing material useful to someone preparing an act of terrorism and conspiracy to inspire racial or religious hatred.

The youngest was detained on suspicion of encouraging terrorism, disseminating terrorist publications and conspiracy to inspire religious or racist hatred.

The 18-year-old was arrested on suspicion of encouraging terrorism and disseminating terrorist publications.

By Sam Blewett