A far-right teenager who branded the Duke of Sussex a race traitor in an "abhorrent" online post has been jailed for four years and three months.

University student Michal Szewczuk, 19, created an image of Prince Harry with a pistol to his head against a blood-spattered background.

The picture, which also included a blood-smeared swastika, was shared on a far-right social media platform in August last year, just a few months after the duke married mixed race former actress Meghan Markle.

The post featured the phrase: "See Ya Later Race Traitor".

The 19-year-old was ordered to be detained in a young offenders' institution after pleading guilty to two counts of encouraging terrorism and five counts of possession of terrorist material, including the White Resistance Manual and the Al Qaeda Trading Manual.

Szewczuk of Wyther Park in Bramley, Leeds, also wrote an "extremely violent and aggressively misogynistic" blog which attempted to justify the rape of women and children in the pursuit of an Aryan race.

He was sentenced at the Old Bailey alongside 18-year-old Oskar Dunn-Koczorowski, from St Albans Avenue, west London, who had admitted two counts of encouraging terrorism.

Judge Rebecca Poulet QC said the pair promoted the extreme violent ideology of right-wing groups inspired by racist and anti-Semitic neo-Nazism.

Referring to the image of Harry, Ms Poulet said: "The posts I have seen and read are abhorrent as well as criminal by reason of their clear intention to encourage terrorist acts."

She told Szewczuk: "Individuals were urged to go out and commit appalling acts of violence on others for no reason that can ever be understood by any right thinking individuals."

Handing Dunn-Koczorowski an 18-month detention and training order, she said: "You still hold deeply entrenched views in support of this extreme right-wing ideology."

The defendants, who were both said to be of Polish descent, had only ever met in online chatrooms.

They were arrested in December after posting images or links to Gab, a social media platform which attracts mainly far-right users.

One of the extremist groups involved in the site, Atomwaffen Division, was described to the court as "a youth-driven, national socialist group at the extreme end of the revolutionary right-wing spectrum" and has been linked to five murders in the US since 2017.

Dunn-Koczorowski, whose posts included support for far-right terrorist Anders Breivik and the threat of ethnic cleansing of Albanians, demonstrated a "highly radicalised and violent mindset", the court heard.

His lawyer, David Kitson, quoted from a medical report which said the teenager had a "lack of remorse" for his views and a "deeply entrenched ideology".

He admitted that Dunn-Koczorowski's mindset had not changed since the offences were committed.

Prosecutor Naomi Parsons said the posts, made across three accounts by the two youths "convey a message of the threat of and/or use of serious violence against others, in order to advance a political, ideological and racial cause (neo-Nazism) and in this way encourage terrorism".

She told the court that targets included Jewish people, non-white people and anyone "perceived to be complicit in the perpetuation of multi-culturalism".

Dunn-Koczorowski was just 17 at the time of the offences and was living at home.

Szewczuk, who was arrested at his halls of residence during his first year studying computer science at Portsmouth University, had a "difficult and disordered upbringing" and had suffered with depression "for a considerable period", his lawyer, Adam Morgan, said.

The court heard that he moved to the UK from Poland at the age of 10, living first in Northern Ireland, and then England.

The defendants appeared in court via video-link from Belmarsh Prison and gave no reaction as they were sentenced.