A Texas man is facing charges of threatening an attack on the University of Houston after he "Zoom-bombed" an online class and praised the Islamic State group, the Justice Department said Tuesday.

Ibraheem Ahmed Al Bayati, 19, disrupted the lecture being held via the online conference service Zoom last Wednesday.

When he got a chance to speak, Bayati said, "What does any of this have to do with the fact that UH is about to get bombed in a few days?" drawing gasps from the other students, according to an indictment.

He then said twice an Arabic phrase that means, "Islamic State will remain," and pointed his index finger toward the sky, a gesture common with Islamic fundamentalists.  Bayati admitted his acts on Friday after he was tracked by his online IP address and arrested by FBI agents at a relative's house.

But he told agents it was just a joke, showing them text messages from a friend which included a link to the Zoom class.

After he joined the class, his friend texted him: "say some Arabic shit and leave lmaooooo."  But investigators further searched his phone and found communications with another friend in which Bayati discussed recruiting supporters of Islamic State, which the United States has designated a terror organization.

Bayati discussed getting another person to pledge allegiance to Islamic State and told his friend "that he was 'literally known' as an ISIS recruiter," the charges said. Bayati was charged with two counts related to making a bomb threat against the university, with a possible total of 15 years in prison.

He was to appear in federal court in Houston Tuesday afternoon.