KUALA LUMPUR, Malaysia - Investigators are trying to learn all they can about two passengers who boarded a missing Malaysian jetliner with stolen passports.
Thai police and Interpol are questioning the proprietors of a travel agency in a Thai resort town that sold the men one-way tickets.
Malaysia's police chief was quoted by local media as saying that one of the men has been identified, but Malaysia's civil aviation chief isn't confirming that.
The use of stolen passports has fueled speculation that terrorists may have brought down the Boeing 777, which vanished with 239 people aboard.
The police agency says it has a database of 40 million stolen or lost travel documents -- but that last year, more than a billion times, travelers boarded planes without their passports being checked against the database. Another possible clue to the disappearance of a Malaysian jetliner has turned out to be unconnected to the plane.
Malaysian maritime investigators had found some oil slicks in the South China Sea, and sent a sample to a lab to see if the oil came from the missing plane. However, they now say tests show the oil was not from an aircraft.
Earlier, searchers investigated a yellow object that looked like a life raft. It turned out to be trash covered with moss that was floating in the ocean.
The head of the organization that monitors the nuclear test ban treaty says he has asked its experts to see if they detected an explosion at high altitude of the missing plane.
Lassina Zerbo, executive director of the Comprehensive Nuclear Test Ban Treaty Organization, says the CTBTO uses "infrasound" - or infrasonic sensors - to monitor the earth mainly for atmospheric nuclear explosions.
Zerbo says infrasound is the most suitable technology to check if there was an explosion on the missing plane and if there was a monitoring station nearby, "or the explosion is at a level or at an amplitude that it could be detected."
He says he has asked the head of the CTBTO's International Data Center to examine the infrasound data.