Jet transponders possibly turned off

US counterterrorism officials are reportedly trying to find out whether someone on board the missing Malaysian airliner intentionally turned off the aircraft’s transponders to avoid radar detection.

The Wall Street Journal has reported that the officials are exploring the possibility that the aircraft was diverted towards an undisclosed location after the pilot or some other person on the flight turned off the transponders.

At one briefing, US officials were told investigators are actively pursuing the notion that the plane was diverted “with the intention of using it later for another purpose,” the journal said.

According to the paper, US investigators suspect that Malaysia Airlines Flight 370 stayed in the air for about four hours past the time it reached its last confirmed location.

The hunt for the aircraft entered its sixth day on Thursday.

The Malaysia Airlines Boeing 777-200ER went missing on its way from Kuala Lumpur to Beijing on Saturday, after taking off with more than 239 people on board.

The head of the US Central Intelligence Agency says terrorism cannot be ruled out in the recent disappearance of the Malaysian passenger plane.