Sick ISIS supporters appear to be celebrating the deaths of three people and an attacker in London during a terror attack on Westminster.
Messages have been shared on an unofficial 'ISIS Telegram Channel' sharing the news of the attack in Westminster on Wednesday afternoon, with people writing 'Allahu Akbar'.
According to Ahmet Yayla, a senior research fellow at the International Centre for the Study of Violent Extremism (ICSVE), the messages are being shared on a 'credible' ISIS channel.
He shared screengrabs on his Twitter account, showing content of groups where messages included 'blessed London attack'.
One user shared pictures of the route the attacker took across Westminster Bridge and into the gates of Parliament, while another shared this website's headline of 'Terror at Westminster'.
In other apparent messages from supporters, a picture shows a mocked-up image of the Elizabeth Tower on fire.
The message with the smoke billowing out reads: 'Soon. Our battle upon your land.
'Not started yet.
'Be upon you. Only waiting.'
Rita Katz, director of SITE Intelligence Group, said the lack of media campaign from ISIS could show there was no coordination with ISIS if it was linked with the terror group.
Similar pro-ISIS 'channels' shared blow by blow updates after the attacks in Nice, Paris and Orlando.
ISIS claim on an event can be 24 hours afterwards, and usually not until the attacker is confirmed dead, according to terror experts.
Other ISIS chat rooms show mocked up images of fighters super imposed over the Houses of Parliament, according to a paper by the ICSVE.
The paper reveals ISIS supporters have been urged and shown how, to carry out attacks with vehicles.