WASHINGTON — The FBI is deploying agents and technical experts to assist in investigating the disappearance of a Malaysia Airlines jet, based on the American citizenship of three of the passengers aboard the lost flight, a top federal law enforcement official in Washington said Saturday.
He said that a fourth passenger, whom he described as an infant flying with the three Americans, also may be a U.S citizen.
"This gives us entree" to the case, the official said, speaking confidentially because the FBI investigation is just beginning. "But so far what happened is a mystery."
U.S. officials said they are looking at whether this could be terrorism, as they would with any plane crash until proved otherwise. Though two passengers apparently used stolen passports, “there is no indication this is a terrorist attack; stolen passports are certainly not indicative of a terrorist attack,” a senior counter terrorism official said.
The official said there was "no evidence" of terrorism thus far. Law enforcement officials were not authorized to speak publicly.
The federal law enforcement official said FBI personnel will assist in reviewing video of the airport in Kuala Lumpur for images of passengers at the ticket counter, the security sections and the boarding area. He said images they find can be used with the bureau's vast counter-terrorism technology to look for matches with known members of Al Qaeda or other terrorist organizations.
But he emphsized that no known terrorist link has surfaced, and no organization has claimed responsibility for downing the plane, which was en route to Beijing with 239 people aboard when it disappeared from air traffic control monitoring.
Vietnamese military aircraft participating in a search-and-rescue operation for the plane spotted two oil slicks off the coast of southern Vietnam that were consistent with a plane crash, the Associated Press reported, but there has been no verification that they were associated with the missing jet.
The U.S. law enforcement official said that the federal National Transportation Safety Board will also probably be brought into the investigation "because the jet was built by Boeing in this country."
An official at the Department of Homeland Security said it would be a first if the plane was brought down by two terrorists who boarded the jet carrying stolen passports. "We've never seen that," he said.
He noted that in the United States, passports and other travel documents are immediately run through a computer database that would have detected whether they had been stolen or lost. In Malaysia, however, the security arrangement is not as tight, he said, and purloined travel documents could have gotten two of the passengers through the security checkpoints.
He cautioned that at this early stage, "we can't say what it means yet." But he said that the two stolen passports have given investigators an open door to look for security breaches.
The Homeland Security source said that the passport stolen from an Italian was taken from his rental car when he returned the vehicle in August in Malaysia. The second passport was stolen from an Austrian man two years ago, he said.
"Just because they were stolen doesn't mean the travelers were terrorists," the Homeland Security source cautioned. "They could have been nothing more than thieves. Or they could have simply bought the passports on the black market."
Another U.S. law enforcement official said Interpol keeps a registry of lost and stolen passports that major international airlines routinely check before passengers board a flight. It would be unusual for a passenger on a major airline such as Malaysian Airways to be able to board using a stolen passport, he said.
Passenger manifests of international flights are checked against intelligence databases if there is a leg that departs or lands in the United States. But the jetliner that disappeared en route from Kuala Lumpur to Beijing did not have a U.S. leg on its itinerary.
Times staff writers Ken Dilanian and Brian Bennett contributed to this report.