Sources: Terror suspects may be U.S. citizens

WASHINGTON (AP) - At least two of the three men involved in a possible al-Qaida plot to pull off an attack coinciding with the 10th anniversary of 9/11 are believed to be U.S. citizens or have U.S. traveling documents, government officials said Friday.

Their primary mission is to explode a car bomb in either New York or Washington, but if that proves impossible, they have been ordered to simply cause as much destruction as they can, one U.S. official said.

Word that al-Qaida had dispatched would-be attackers reached U.S. officials midweek. A CIA informant who has proven reliable in the past approached intelligence officials overseas to say that the men had been ordered by newly minted al-Qaida leader Ayman al Zawahri to mark the 10th anniversary of the 9/11 attacks Sunday by doing harm on U.S. soil.

The tipster says the would-be attackers are of Arab descent and may speak Arabic as well as English. Counterterrorism officials were looking for certain names associated with the threat, but it was unclear whether the names were real or fake.

Counterterrorism officials have been working around the clock to determine whether the threat is accurate, but so far, have been unable to corroborate it, the officials said, speaking on condition of anonymity to discuss the investigation.

In the meantime, extra security was put in place to protect the people in the two cities that took the brunt of the jetliner attacks that killed nearly 3,000 people at the World Trade Center and the Pentagon a decade ago. It was the worst terror assault in the nation's history, and al-Qaida has long dreamed of striking again to mark the anniversary. But it could be weeks before the intelligence community can say whether this particular threat is real.

Undaunted by talk of a new terror threat, New Yorkers and Washingtonians wove among police armed with assault rifles and waited with varying degrees of patience at security checkpoints Friday.

Security worker Eric Martinez wore a pin depicting the twin towers on his lapel as he headed to work in lower Manhattan on Friday where he also worked 10 years ago when the towers came down. "If you're going to be afraid, you're just going to stay home," he said.

Mayor Michael Bloomberg, too, made a point of taking the subway to City Hall.