Hawzah News Agency - A far-right Norwegian man was jailed for 21 years for the racially motivated murder of his Chinese-born stepsister and attempting to kill worshippers in a mosque shooting spree.

Philip Manshaus expressed strong anti-immigrant and anti-Muslim views before last year's attack and was unrepentant at trial.

Manshaus, now 22 years old, shot and killed Johanne Zhangjia Ihle-Hansen in their family home, later explaining he believed the adopted daughter of his father's spouse posed a risk to the family because of her Asian origin.

He then drove to the nearby Al-Noor Islamic Centre and entered the building, firing several shots but hitting no one before being overpowered by a 65-year-old member of the congregation who wrestled away his guns.

"He went in with the purpose of killing as many Muslims as possible," judge Annika Lindstroem said.

Manshaus expressed admiration for the massacre of more than 50 people at two New Zealand mosques last year by a white supremacist who filmed and broadcast the killings live.

The attack also drew comparisons with the massacre of 77 people by far-right mass killer Anders Behring Breivik in 2011 in Norway's worst peacetime atrocity.

Manshaus wore a helmet camera, filming the mosque shooting, but failed in his attempt to broadcast the attack online.

In his first court hearing last August, Manshaus appeared with black eyes and bruises on his face and neck from the ensuing fight at the mosque.

The court rejected the defence's plea to declare Manshaus insane, relying instead on a psychiatric evaluation which found him fit to stand trial.

The 21-year prison term, the steepest available for the first-degree murder and breach of anti-terrorism law, also contained a provision that his release can be put off indefinitely should he still be considered a threat to society.