The head of the US Central Intelligence Agency said on Tuesday that terrorism could not be ruled out in the disappearance of a Malaysian airliner.
CIA Director John Brennan said there had been "some claims of responsibility" over the missing jet that had "not been confirmed or corroborated," and that he could not exclude the possibility of a terror link.
He provided no further details, but his comment was the first reference by a US official to any alleged claim of responsibility over the jet's fate.
When asked if he could rule out a terrorist link, Brennan said: "No, I wouldn't rule it out."
Brennan, the former counter-terrorism adviser to President Barack Obama, said there were many unanswered questions and it was too early to reach any conclusions about the Malaysia Airlines plane that vanished Saturday with 239 people on board after taking from Kuala Lumpur en route to Beijing.
"We are looking at it very carefully," he said. "Clearly this is still a mystery."
In a rare public speaking appearance, Brennan gave a speech and answered questions at an event in Washington organized by a think tank, the Council on Foreign Relations.