Kuala Lumpur: More than four days after a Malaysian jetliner went missing en route to Beijing, authorities acknowledged Wednesday they didn't know which direction the plane carrying 239 passengers was heading when it disappeared, vastly complicating efforts to find it.
Amid intensifying confusion and occasionally contradictory statements, the country's civil aviation authorities and the military said the plane may have turned back from its last known position between Malaysia and Vietnam, possibly as far as the Strait of Malacca, a busy shipping lane west of Malaysia.
How it might have done this without being clearly detected remains a mystery, raising questions over whether its electrical systems, including transponders allowing it to be identified by radar, were either knocked out or turned off.
If it did manage to fly on, it would challenge earlier theories that the plane may have suffered a catastrophic incident, initially thought reasonable because it didn't send out any distress signals.
Vietnamese officials gave conflicting accounts of whether the search effort there was being scaled back as a result of the confusion. This likely will anger relatives of those on board who are desperate for information about the fate of their loved ones.
Authorities have not ruled out any possible cause, including mechanical failure, pilot error, sabotage or terrorism. Both the Boeing 777 and Malaysia Airlines have excellent safety records. Until wreckage or debris is found and examined, it will be very hard to say what happened.
The search for the missing aircraft was begun from the spot it was last reported to be over the ocean between Malaysia and Vietnam. But Malaysian authorities have said search operations were ongoing in the Strait of Malacca. Scores of planes and aircraft have been scouring waters in both locations.