ISIS supporters have already expressed delight at the stabbing attack in London that left one American woman dead and five people injured.

In the hours after the attack ISIS linked accounts on social media were soon reporting the news of the stabbings in a tourist hotspot in the heart of the British capital.

US counter terrorism analyst Michael S. Smith posted on Twitter that the volume of communications in ISIS-linked social media accounts was 'low'

ISIS supporters have already expressed delight at the stabbing attack in London that left one woman dead and five people injured.

According to Michael S. Smith II, a US based expert for the Congressional Taskforce on Terrorism and Unconventional Warfare, IS-linked social media channels spread the news in the early hours of this morning UK time.

The ISIS-linked group account on private social media channels linked to on Twitter published pictures on the aftermath of the attack.

The Arabic-language account, called the ‘News Publishing Service’, which has a logo incorporating a rifle said: 'Here you have a picture of the site where the stabbing took place, Russell Square in the centre of 'Christendom' London.'

It was also reported that an Arabic-language account wrote that 'It’s nice to wake up to such news'.

Mr Smith wrote on Twitter that the volume of communications in ISIS-linked social media accounts was 'low'.

Police have confirmed that they have no reason to believe the knife man - a 19-year-old Norwegian national of Somali origin - had been radicalized.

The account wrote: 'And here you have a picture of the site where the stabbing took place, Russell Square in the centre of 'Christendom' London'

Britain's top anti-terror officer Mark Rowley said they have now interviewed the suspect, spoken to his family, searched his London home and liaised with MI5 and MI6 and believe it was a 'spontaneous' and 'random' attack, not 'motivated by terrorism'.

Defending his decision to suggest terrorism as a motive earlier today he said: 'You would expect us in the current climate to consider all possibilities'.

It was also reported that an Arabic-language account wrote that: 'It’s nice to wake up to such news'

Mr Smith monitors more than 50 ISIS-linked social media channels that spread breaking news to invite-only followers on private networks in a bid to incite violence.

While the accounts don't celebrate the news of violence directly, he says the reactions to ISIS-led attacks are like a 'jihadgasm', where as reports of random acts of violence are met with passing interest.

'After [the lorry terrorist attack on Bastille Day in] Nice there was an explosion immediately after on Telegram and on Twitter,' he told MailOnline.

'It’s common where you have the reporting in Europe of violent events – like Munich and London last night - there's interest but you don’t see the same confidence that it was an ISIS attack as you would see with Nice.'