The Archbishop of Canterbury has labelled the far-right “unchristian” and condemned the use of Christian imagery in the riots as “an offence to our faith”.

Justin Welby made the remarks condemning the violent unrest, which he described as “racist”, “anti-Muslim, anti-refugee”, in an article for the Guardian newspaper.

The country’s most senior Christian leader weighed in following a week of disorder that began after a mass stabbing of children at a Taylor Swift-themed dance class in Southport in July.

Rioters attacked police, mosques, shops, and a hotel housing asylum seekers after incorrect rumours that the suspect in the stabbings was an asylum seeker who arrived in the UK on a small boat were spread via social media, appearing to fuel the unrest.

Police had arrested 779 people in connection with the rioting, the National Police Chiefs’ Council said on Saturday.

The archbishop’s article centred on imploring Christians to distance themselves from the far-right, writing: “Let me say clearly now to Christians that they should not be associated with any far-right group – because those groups are unchristian.”

He added that Christian iconography had been “exploited” by the far-right and served as “an offence to our faith”.

Speaking directly to Muslims and other faiths, Mr Welby said: “We denounce people misusing such imagery as fundamentally antichristian.”

Mr Welby said the riots were “detonated by lies and fuelled by deliberate misinformation, spread quickly online by bad actors with malignant motivations.”

He went on: “The lies and misinformation flourished in fertile ground cultivated by years of rhetoric from some of our press and politicians, arriving at a point where some felt emboldened to try to set fire to a hotel housing asylum seekers and target mosques.”

The archbishop also rejected the description of the riots as “protests” and said they were “criminal” and “must be controlled”.

He also praised efforts by the public aimed at healing tensions, including an imam in Liverpool who offered food to a small group of protesters at a mosque and bricklayers in Southport who helped to rebuild a mosque that had been vandalised.

“We must develop and cherish these examples of civic virtue that have been counter-messages to those of the mob,” he said.

It is not the first public statement the archbishop has made on the recent disorder.

On Tuesday, he told BBC’s Today programme: “This is not the United Kingdom. It’s not British. It’s not English. They defile the flag that they wrap themselves in.”