Man arrested for threats to Washington subway

WASHINGTON (Reuters) - A Virginia man has been arrested for making threats to use explosives in the Washington, D.C., area, including in the local subway system, according to court documents released on Tuesday.

A federal court affidavit by an FBI agent said the man, Awais Younis, allegedly had described to another person how to build a pipe bomb and what type of shrapnel would cause the greatest amount of damage.

The court documents said the suspect, who lives in Arlington, Virginia, and is believed to be an Afghan native, had recently stated on Facebook that "Christmas trees were going to go boom."

There is no indication from the court documents that an attack was imminent and Younis was charged only with "communicating threats using interstate communications."

In October, another Virginia man, Farooque Ahmed, 34, of Ashburn, who allegedly believed he was helping al Qaeda plan bombings at Washington area Metrorail stations, was arrested in a sting operation and U.S. officials said the public was never in any danger.

Justice Department spokesman Dean Boyd said Younis was arrested on December 6 and that he has not been charged with any federal terrorism violations.

"The public should be reassured that his activities prior to his arrest were carefully monitored and that there is no threat against Metrorail or the general public in the Washington, D.C., area," Boyd said in a statement.

According to the affidavit, the unidentified person had contact with Younis through the online social networking site Facebook last month in which he allegedly said he could place a pipe bomb under a sewer in the Georgetown neighborhood during rush hour to produce the greatest number of casualties.

He also allegedly described how he could place pipe bombs in the third and fifth cars of the subway trains, which had the highest number of commuters, the FBI agent said.

(Editing by Cynthia Osterman)