A South Florida man who allegedly posted illegal bomb-making instructions online while declaring his support for Islamic extremists was arrested Friday on terrorism-related charges, according to an FBI complaint unsealed Monday.

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The affidavit charges Tayyab Tahir Ismail, 33, of Pembroke Pines, with posting the illegal bomb instructions through a mobile messaging platform at least five times between July and September, the Sun-Sentinel reported. If convicted, Ismail could receive a maximum of 20 years in prison, the newspaper reported.

The FBI says Ismail, a naturalized U.S. citizen from Pakistan, posted other messages of support for the Islamic State and did searches on how to build bombs, WPLG reported.

According to the affidavit, "Ismail was a member of various rooms within the platform and each of these rooms contained members who support violent jihad," the Miami Herald reported.

"You are surrounded by methods to hit them. Kill the devil's soldiers without hesitation. Make them bleed even in their own homes," according to one message Ismail allegedly shared online. "There are plenty of methods to attack my brother."

The FBI affidavit said explosives experts believe the bomb instructions Ismail posted were accurate, the Sun-Sentinel reported.

According to the warrant, the FBI first became aware of Ismail in 2010, when he allegedly made terrorist threats at a homeless shelter, WPLG reported.

Ismail is scheduled to appear in court Dec. 26, the Sun-Sentinel reported.