Los Angeles ? A Pakistani national has been arrested in a terrorism investigation into a possible plot to attack the Israeli Consulate, California National Guard facilities and other targets, officials said Tuesday.

Hammad Riaz Samana, 21, was taken into custody on Aug. 2 and has been detained in Los Angeles, according to the U.S. Bureau of Prisons.

His arrest came after investigators discovered a potential target list at the home of Levar Haney Washington, who has been implicated in a series of gas station robberies in Los Angeles County, according to a law enforcement official who asked to remain anonymous because of the sensitivity of the investigation.

The list included three National Guard facilities in the Los Angeles area, as well as the Israeli Consulate and a couple of synagogues.

Washington, 25, was arrested July 5 for investigation of robbery. Also arrested was Gregory Vernon Patterson, 21.

Both men have pleaded not guilty to the charges in Torrance Superior Court.

It was unclear what connection, if any, Samana had to Washington and Patterson. Cathy Viray, an FBI spokeswoman, declined to comment, saying the investigation by federal and local agencies was ongoing.