ISIS supporters celebrated the terrorist attack at an Ariana Grande concert in Manchester, England, on Monday night, issuing warnings that the attack was “only the beginning.”

“Are you forget our threat? This is the just terror,” posted one account on Twitter following the deadly attack that took 22 lives and left 119 wounded. “In the name of Allah the merciful.”

“Kill Him everywhere,” posted another, with the Manchester hashtag and an ISIS picture, while an account under the name of Abdul Haqq tweeted: “It seems that bombs of the British Air Force over children of Mosul and Raqqa has just came back to #Manchester.”

According to The Daily Mail, “Others shared messages encouraging lone wolf attacks as well as videos threatening the west and the United States,” and a masked man declared “This is only the beginning,” during an unverified surfaced video.

“Others posted banners saying ‘the beginning is in Brussels and Paris, and in London we form a state,'” added The Independent.

Many supporters of the Islamic terror group also flocked to the encrypted messaging service Telegram, where they celebrated the attack.

SCREENSHOTS Growing celebrations of situation in #Manchester on key Islamic State-linked Telegram channels. Strong indicator of IS linkage pic.twitter.com/RSJBt0gJcR — Michael S. Smith II (@MichaelSSmithII) May 23, 2017

Key Islamic State-linked Telegram channels that have celebrated #Manchester attack now spreading words re Pound loss relative to Dollar pic.twitter.com/3IX3rcw7d5 — Michael S. Smith II (@MichaelSSmithII) May 23, 2017

Hey Islamic State cheerleaders, I'm watching you post screenshots I tweeted re #Manchester on Telegram channels. Is "idiot" all you've got? pic.twitter.com/K2t3EraiOE — Michael S. Smith II (@MichaelSSmithII) May 23, 2017

Charlie Nash is a reporter for Breitbart Tech. You can follow him on Twitter @MrNashington or like his page at Facebook.