Washington, Oct 28 (DPA) A US citizen of Pakistani origin was arrested Wednesday on charges related to plotting to attack the rail transit system in the Washington area, authorities said.

Farooque Ahmed, 34, has been charged with attempting to provide material support to a known terrorist organisation and gathering information to assist in an attack, the justice department said.

The justice department said Ahmed was interacting with individuals "whom he believed to be members of Al Qaeda" in planning multiple bombings on Metrorail stations just outside the nation's capital.

The justice department said the plot never materialised.

"Today's case underscores the need for continued vigilance against terrorist threats and demonstrates how the government can neutralise such threats before they come to fruition," Assistant Attorney General David Kris said.

Ahmed faces up to 50 years in prison if convicted and was due to appear later Wednesday in federal court. He was suspected in a plot to carry out simultaneous attacks on several stations some time in 2011.

The justice department alleges that from April to October, Ahmed accepted documents from a courier he believed was affiliated with Al Qaeda. The documents outlined potential targets in Arlington, Virginia, a suburb of Washington.

On several occasions, Ahmed gathered video of Metrorail stations in Arlington and provided the purported Al Qaeda operatives with a digital recording of the footage, the justice department alleges.

Further, Ahmed is suspected of drawing diagrams of three Metrorail stations in Arlington and providing to an individual he believed to be an Al Qaeda agent suggestions as to where to plant explosives to kill the most number of people.