ISIS supporters are threatening more violence and coordinating a social-media response to the Brussels attacks

Supporters of the terrorist group ISIS are coordinating a response to the terror attacks in Belgium on Tuesday morning, asking other supporters to tweet certain phrases and threatening more violence.

An account on the secure-messaging app Telegram, which ISIS-affiliated supporters use to distribute statements and propaganda, has posted several tweet templates for others to use as they comment on the attack on Twitter, though it remains unclear who is responsible for the attacks.

The Telegram channel, which has more than 1,100 subscribers, is unofficially affiliated with ISIS and is focused on posting the tweets of other supporters of ISIS (also known as the Islamic State, ISIL, or Daesh).

Hours after an explosion rocked the Brussels airport and another hit a suburban metro station, killing dozens, the channel announced a "Twitter campaign." It directed supporters to "tweet the following five tweets massively on Twitter."

The tweets are in French. They contain threats - one reads, "We will kill you all with knives, guns, and bombs - as well as hashtags like "#Brussels," "#Bruxelles," "#Paris," and "#BrusselsLockdown," and warnings of upcoming attacks in Germany.

"Expect more bombs, more death!" one tweet read. "Coming soon in Germany!"

ISIS supporters mounted a similar effort on social media after the ISIS attacks in Paris in November.

Charlie Winter, an expert on jihadist propaganda and a senior research associate at Georgia State University's Transcultural and Violence Initiative, noted that, while there is a lot of online "noise" from ISIS supporters, there has been no official claim of responsibility from ISIS for the Brussels attacks.

The Telegram channel that posted the tweets is a "fanboy account," Winter told Business Insider. But the tweets do bear similarity to ISIS supporters' response in the wake of the Paris attacks, he said.

"A very similar thing happened in wake of Paris," Winter said via email. The coordinated response after Paris came from "accounts like this one," he said, referring to the Telegram channel that posted the tweets on Tuesday.

And though experts say it appears unlikely that Twitter responses from ISIS supporters would be directed by the group's central leadership based in the Middle East, it's possible that some people linked to ISIS in Europe did know of the attack in advance.

"It doesn't take long to put together a few tweets," J.M. Berger, an expert on terrorist social-media use and coauthor of the recent book "ISIS: The State of Terror," told Business Insider in an email. "But typically, and especially post-9/11, a terrorist cell in the field has some discretion about timing and targets."

More broadly, ISIS supporters are celebrating the Brussels attacks on Twitter. Top ISIS-affiliated accounts are encouraging supporters to use hashtags affiliated with the attacks to blast out the group's propaganda.