U.S. officials are considering raising the nation's terror alert after two tapes surfaced this week, one from Usama bin Laden (search) and the other from a man who identified himself as "Azzam the American," sources told FOX News.

The terror alert level now stands at "yellow" — or elevated — for most of the country but officials told FOX News it may be raised to "orange" — or high. A number of high-level meetings were held Saturday on the matter, sources said. 

White House spokesman Scott McClellan (search) sought Saturday to play down that possibility. And he said President Bush's campaign schedule would not be changed because of the tapes.

"That's something we're always reviewing and looking at, but there is no change at this time. We are already on a heightened state of alert. Remember, we're in an increased period of risk already and we have taken a number of steps related to that, some of which you see and some of which are not seen," McClellan said.

Bush held a videoconference call with national security adviser Condoleezza Rice (search) and the heads of the CIA, FBI and departments of Justice and Homeland Security. "The president did direct them to make sure we were taking all actions that might be necessary," he said.

On Friday, the Al-Jazeera television network aired portions of the 18-minute tape by bin Laden, the Al Qaeda leader who took responsibility for the Sept. 11, 2001, attacks on the United States. Although bin Laden did not make any direct threats against Americans, he did say that the United States must stop threatening the security of Muslims if it wants to avoid "another Manhattan."

Bin Laden also issued a warning. "There are still reasons to repeat what happened," on Sept. 11, he said.

The government has alerted state and local authorities to be extra vigilant ahead of Tuesday's elections.

We remain concerned about Al Qaeda's interest in attacking the American homeland, and we cannot discount the possibility that the video may be intended to promote violence or serve as a signal for an attack," according to the bulletin sent late Friday from the FBI and the Homeland Security Department.

It went to homeland security advisers, state and local police and select members of private industry.

The bulletin said intelligence agencies continue to analyze the tapes.

A U.S. government official said steps have been taken to secure the public and that homeland security officials have been urged to keep vigilant.

Earlier in the week, a tape surfaced where a  man wearing dark glasses and an Arab headdress wrapped around his face claimed to be an American member of Al Qaeda and promised attacks that will make the streets of America "run red with blood."

Multiple officials and terrorist experts suspect the man is Adam Yahiye Gadahn (search), a young American who converted to Islam.

The FBI plans to put up portions on its Website of the "Azzam the American" tape to get people to keep an eye out for Gadhan, law enforcement officials said.

FOX News' Bret Baier, Ian McCaleb and Anna Persky contributed to this report.