HOMELAND SECURITY THREAT LEVEL RAISED TO HIGH - ORANGE

WASHINGTON (CNN) -- Citing credible threats that al Qaeda might be planning attacks on American targets, the U.S. government raised the national color-coded threat level Friday to orange, indicating a "high" risk of a terrorist attack.

The change is only the second time the alert level has risen above yellow, an "elevated" risk, since the system was put in place in the aftermath of the attacks of September 11, 2001.