US officials told The Los Angeles Times that they are trying to determine whether there was any terror link to what caused Flight 370 to go missing as it carried 239 people from Kuala Lumpur toward Beijing.
The fact that at least three of the passengers are believed to be Americans "gives us entree" to the case," a top federal law enforcement official told the newspaper.
"But so far, what happened is a mystery."
A US official told CNN that FBI agents stationed at the American Embassy in Kuala Lumpur, including an FBI legal attache, were monitoring the situation closely.
AFP