(CNN) — This U.S. Department of Homeland Security has issued an unclassified notice stressing security on U.S. railways — an alert prompted, according to a U.S. law enforcement source, by information gleaned from this week’s raid on Osama bin Laden‘s Pakistani compound.
The notice says that, in February 2010, al-Qaida members discussed a plan to derail trains in the United States by placing obstructions on tracks, according to a source who received the notice.
