He was arrested after taking possession of the explosives and weapons and locking them in a storage unit, the Justice Department statement said. It stressed that the undercover agents were in direct possession of the explosive devices and the public was not in danger from them.
The FBI sought to head off any violence that could be motivated by the news of the arrest.
"It is important to remember that our system of justice is based on the notion of individual responsibility," said Richard DesLauriers, the special agent in charge of the FBI's Boston division. "Therefore, no one should cite Mr. Ferdaus' actions as an excuse or reason to engage in any unlawful behavior against others in the community. We will work diligently to protect the civil rights of all Americans."
If Ferdaus is convicted, he faces up to 15 years in prison on charges of supporting a foreign terrorist organization; up to 20 years in prison on charges of attempting to destroy national defense premises; and up to 20 years in prison on a charge of attempting to damage and destroy U.S. buildings with an explosive.
Ferdaus also faces up to three years of supervised release and a $250,000 fine on each charge.