This article is more than 1 year old

This article is more than 1 year old

The suspected gunman in an attack on a mosque in Norway on Saturday was inspired by recent white extremist attacks in New Zealand and the US, online posts suggest.

Police in Norway have so far only said the attack in Baerum, a town 20km from Oslo, the capital, will be investigated as a possible act of terrorism.

Timeline A history of recent attacks linked to white nationalism Show Hide In the past decade, across continents, white supremacists have repeatedly chosen the same targets for shootings, stabbings, bombings and car attacks. Utøya island and in Oslo, Norway 77 killed in a bomb attack, followed by a shooting targeting the island summer youth camp of Norway’s Labor party. The shooter wanted to prevent an 'invasion of Muslims' and deliberately targeted politically active young people who he saw as 'cultural Marxists'. More than half of the dead were teenagers.

Sikh temple in Oak Creek, Wisconsin, US Six worshippers including the temple president are killed. The shooter, a ''frustrated neo-Nazi' who had played in white power bands, was a regular on racist websites. He had previously talked to one colleague in the US military about a 'racial holy war that was coming'. Piraeus, Greece Rapper and anti-fascist activist Pavlos Fyssas was stabbed to death. A senior member of Greece’s neo-Nazi Golden Dawn party was imprisoned after confessing to the killing. Overland Park, Kansas, US A former Ku Klux Klan leader shot and killed three people at a Jewish centre and retirement home, one of them just 14 years old. He said he believed Jews were destroying the white race, and that diversity was a kind of genocide. Charleston, South Carolina, US Nine people killed during Bible study at a historic black church. The victims included elderly longtime church members at the Mother Emanuel AME church, and Clementa Pinckney, a state senator. The shooter, a self-avowed white supremacist, said he wanted to start a race war.

Trollhättan, Sweden An attacker stabbed students and teachers at a high school, targeting those with darker skin, police said. Three died, including 15-year-old Ahmed Hassan, who was born in Somalia and had recently moved to Sweden. Birstall, West Yorkshire, UK Labour MP Jo Cox shot and stabbed to death a week before the EU referendum vote in 2016. The man convicted of killing her, a white supremacist obsessed with the Nazis and apartheid-era South Africa, shouted: 'This is for Britain,' 'Keep Britain independent' and 'Britain first' as he killed her. Quebec City, Canada Six people killed and nineteen injured during evening prayers at a mosque in a shooting which the gunman said was prompted by Justin Trudeau’s tweet that refugees were welcome in Canada, and that 'diversity is strength'. New York, US Timothy Caughman stalked and killed by a white supremacist with a sword. His killer, an American military veteran, said he targeted a random black man on the street in New York City as a 'practice run' for a bigger attack, and as part of a campaign to persuade white women not to enter into interracial relationships. Portland, Oregon Two men were killed and one injured after they tried to intervene to protect young women on a public train who were being targeted with an anti-Muslim tirade. Their alleged killer shouted 'Free speech or die' in the courtroom, and 'Death to Antifa!' Finsbury Park, London, UK One killed and 12 people injured after a van ploughed into worshippers outside a mosque. The killer shouted 'I want to kill all Muslims – I did my bit' after the van attack. A judge concluded he had avidly consumed anti-Muslim propaganda from prominent rightwing figures. Charlottesville, Virginia, US Heather Heyer killed and dozens injured after a car ploughed into anti-Nazi protesters. The killer had been obsessed with Hitler as a teenager, according to a former teacher. Kentucky, US Man attempted to enter black church before allegedly killing two black people in a supermarket. A witness said that during the attack, the alleged shooter said: 'Whites don’t kill whites.' Pittsburgh, Pennsylvania, US 11 killed in a mass shooting targeting the Tree of Life synagogue. The alleged shooter had an active profile on an extremist social media site, where he accused Jewish people of trying to bring 'evil' Muslims into the US, and wrote that a refugee aid organisation 'likes to bring invaders in that kill our people'. Christchurch, New Zealand 51 people were killed and 49 injured in two consecutive attacks on mosques during Friday prayers. The gunman live-streamed the first attack on Facebook Live. They opened the live stream by urging viewers to 'subscribe to PewDiePie', a meme used by the online alt-right and white supremacists. Poway, California One person killed in mass shooting targeting a synagogue in Poway, California, US. The alleged shooter, 19, from California, opened fire in a synagogue during Passover services, killing a 60-year-old woman and injuring three others. An“open letter” posted on the 8chan extremist message board before the attack included white nationalist conspiracy rhetoric and said the shooter was inspired by the New Zealand mosque attacks. Walmart shooting, El Paso, Texas 21 people killed after a shooter opened fire at a busy Walmart store packed with families shopping. Two dozen more were injured. The 21-year-old white male suspect had driven nine hours to reach his target. and had posted a "manifesto" on 8chan. Lois Beckett and Martin Belam

In messages posted on the day of the attack, Philip Manshaus, a 21-year-old man who has been named by local media as the main suspect, described himself as “chosen” by “Saint [Brenton] Tarrant”, the gunman who killed 51 people at mosques in New Zealand in March.

“My time is up, I was chosen by Saint Tarrant after all … We can’t let this continue, you gotta bump the race war threat in real life … it’s been fun,” one post reads.

In a meme also posted by Manshaus, three rightwing extremists suspected of being responsible for other attacks this year are depicted and praised as heroes of the white nationalist movement.

Tarrant is described as having “addressed the Muslim problem” while Patrick Crusius, who has been charged with the attack in El Paso, Texas, in which 22 people died, is praised for “fighting to reclaim his country”.

A third attacker suspected of killing a woman during a Passover celebration at a synagogue in California in April is also praised, alongside antisemitic abuse.

The evidence of posts supporting the actions of the three suspects will fuel fears that a “cascade” of rightwing extremist attacks is gathering supporters around the world.

“We are now no longer talking about one-off events, but a loosely coordinated chain of far-right attacks across the world, where members of these networks inspire – and challenge – each other to beat each others’ body counts,” said Peter Neumann, professor of security studies at King’s College London.

“The ultimate motivation … is to launch a race war. The aim is to carry out attacks, claim responsibility, explain your action, and inspire others to follow.”

The posts, made shortly before the attack, were both reported to have been on a new messaging board called Endchan, which describes itself as “an anonymous image-board that promotes ideas over identity,” and an older board called 4chan.

A messaging board used by the suspect in El Paso and elsewhere called 8chan was closed following that tragedy.

Unmoderated messaging boards have emerged as a key vector for the spread of extremism.

Neumann said any hopes that shutting down 8chan would deprive the far right of its virtual network looks misguided as supporters quickly move on to other message boards.

Authorities believe Crusius was the author of a racist white nationalist screed that was posted online shortly before the El Paso attack. The author of the document said the attack was “a response to the Hispanic invasion of Texas” and said he was inspired by the gunman in Christchurch.

The post by Manshaus linked to a live stream on his Facebook page – since taken down by the social network.

Witnesses said Manshaus was wearing body armour and was armed with two “shotgun-like weapons” and a handgun.

He was overpowered by people at the mosque before police arrived at the scene. One man was injured in the attack.

Manshaus has been charged with the murder of a woman found dead in his home.