NSA Chief Says Surveillance Programs Have Foiled 50 Terrorist Plots

Including a plan to detonate a bomb on Wall Street

The US government's sweeping surveillance programmes have foiled some 50 terrorist plots worldwide, the director of the National Security Agency has said.

They included a plan to bomb the New York Stock Exchange and another aimed at a Danish newspaper that had published a cartoon image of the Prophet Mohammed.

In a rare open hearing of the House Intelligence Committee, Army General Keith Alexander said the two recently disclosed programmes are "critical" in the fight against terrorism.

The programmes "assist the intelligence community to connect the dots", he told the committee in the Capitol Hill hearing.