"While we know of no specific threats against Texas, we are taking this heightened warning very seriously. I have spoken with Homeland Security Secretary Tom Ridge this morning, and my office will remain in close contact with federal officials.
"The State Emergency Operations Center already has been activated due to the Space Shuttle Columbia tragedy, and we will notify state agencies, health institutions, schools and others to review their security measures and take appropriate actions to guard against terrorism.
"I encourage Texans to be especially vigilant. Be alert and aware of your surroundings and report suspicious activity to your local law enforcement officials at once."