US Vice President Dick Cheney moved to an undisclosed location today and canceled his only public appearance of the day, reflecting heightened security precautions ahead of the first anniversary of the Sept. 11 attacks on America.
The move came as the US government announced it had increased its nationwide threat level, citing information from an al Qaeda source indicating that American targets are at high risk of terrorist attack.
It was the second time in as many days that Cheney was moved to a secret location.
A similar procedure was followed soon after the Sept. 11 attacks, when Cheney spent a substantial amount of time in undisclosed locations to ensure a continuity of government should President George W. Bush be killed. Cheney is next in line for the presidency.
White House spokesman Ari Fleischer said Cheney spent Monday night at a "secure, undisclosed location."
Administration officials said he would do so again Tuesday night, and would not attend a Center for Strategic and International Studies dinner as planned. Cheney was scheduled to address the group. A videotape of his remarks will be aired instead, officials said.
"The vice president is at an undisclosed location at this time," said an administration official, who asked not to be identified.
Cheney worked briefly at the White House on Tuesday morning before returning to hiding.
The White House would not say how long Cheney would remain there, or whether he was moved in response to a specific threat against him or the president.
On the eve of the one year anniversary of the Sept. 11 attacks, Attorney General John Ashcroft announced a change in the country's color-coded threat level to "orange" to reflect the "high risk of terrorist attacks."
Bush said he was not aware of any specific threat to the United States. But he said the threats appeared similar to the pattern before the Sept. 11 attacks.
After the attacks Bush set in motion a Cold War-era plan to keep the government running, sending civilian officials to live and work in secret bunkers outside Washington. Initially a temporary measure, the program was extended indefinitely.
Cheney's absence became apparent on Monday night when he did not show up for a planned appearance with Bush at a Kennedy Center musical commemoration of the attack anniversary.
Fleischer said the decision was based on an "an ongoing review of information that is received" and on other precautions.
"The combination of the two are what makes these determinations necessary," Fleischer said.