A 21-year-old man was arrested on Wednesday for allegedly planning an attack on the White House and other federal buildings.

Authorities arrested Hasher Jallal Taheb of Cumming, Georgia amid a yearlong investigation into his alleged intention to use anti-tank rockets and improvised explosive devices to attack the federal buildings, U.S. Attorney B.J. Pak said at a press conference Wednesday.

The investigation began after a community member sent in a tip in March 2018 that Taheb had become "radicalized" and made plans to travel abroad, according to the criminal complaint. When he was unable to travel abroad due to passport issues, he allegedly began planning an attack in the U.S..

Taheb faces charges of attempts to damage by means of explosive any building owned, possessed, or lease by the United States. Prosecutors plan to bring the case in front of a grand jury, Pak said.

Though Taheb expressed interest in attacking federal buildings, he did not know how to use the weapons he intended to buy, according to the criminal complaint.

Undercover agents were in contact with Taheb throughout his planning discussions and arrested him Wednesday after he tried to buy two backpacks of devices from them, according to the complaint.

Investigators believe Taheb was working on his own, Chris Hacker of the FBI's Atlanta field office said Wednesday.