The U.S. Justice Department said Farooque Ahmed, 34, of Ashburn, Virginia, was arrested Wednesday for attempting to assist others whom he believed to be members of al-Qaida in planning multiple bombings at subway stations in the Washington, D.C., area.

Announcing the arrest, David Kris, Assistant Attorney General for National Security, said, "Farooque Ahmed is accused of plotting with individuals he believed were terrorists to bomb our transit system, but a coordinated law enforcement and intelligence effort was able to thwart his plans."

U.S. Attorney Neil MacBride said the accused intended to target rail stations "with the goal of killing as many Metro riders as possible through simultaneous bomb attacks."

In announcing the arrest, officials said at no time was the public in danger during the investigation and that the FBI was aware of Ahmed's activities from before the alleged attempt began and closely monitored his activities until his arrest. They said the public "should be assured that there was no threat against Metrorail or the general public in the Washington, D.C., area."

White House spokesman Robert Gibbs also said "at no point was the public in any danger." He said the Justice Department, the FBI and national security officials had been on "top of this case from the beginning."