Investigators now believe a Malaysian jet that vanished was commandeered by a "skilled, competent" flyer who piloted the plane for hours, a senior Malaysian military official said on Saturday as Prime Minister Najib Razak prepared to address the nation.
Speaking to AFP on condition of anonymity, the official cited Malaysian military radar data that investigators believe indicate the Boeing 777 may have radically changed course and headed northwest towards the Indian Ocean.
"It has to be a skilled, competent and a current pilot," the official said. "He knew how to avoid the civilian radar. He appears to have studied how to avoid it." Prime Minister Najib's office said on its Twitter account that he would address the media at 1:30 pm (0530 GMT).
It gave no further details, but the official's comments and the planned press briefing raised expectations of a major announcement in the case. Najib has so far left press briefings in the crisis to lower-ranking officials.
The plane's intended flight path for the Kuala Lumpur-Beijing journey was to be north over the South China Sea and Vietnam.
The new information, coupled with multiple corroborative but unconfirmed reports, suggests the investigation into the disappearance of Malaysia Airlines flight MH370 is increasingly focusing on something going wrong in the cockpit.
Analysts have said that could include a sudden loss of cabin pressure or other mechanical event that incapacitated the pilots, catastrophic pilot error, or more sinister possibilities such as the plane being commandeered by a hijacker or rogue member of the flight crew, or pilot suicide.
All signs so far point to a "controlled, deliberate act, not a mechanical failure", said Scott Hamilton, managing director of US-based aviation consultancy Leeham Co. The mounting reports of an unexplained banking to the west have coincided with a shift of search and rescue resources towards the Indian Ocean.
Search extends to Bay of Bengal
A US destroyer and surveillance plane joined expanded search operations Saturday in the Bay of Bengal. The international search effort had focused in its early days on the South China Sea.
Pentagon spokesman Colonel Steven Warren said the USS Kidd guided missile destroyer and a P-8 Poseidon aircraft had been deployed to the "western search area" in the Andaman Sea and Bay of Bengal.
The Boeing 777, with 239 passengers and crew on board, vanished on March 8 over waters between Malaysia and southern Vietnam. The night was clear and no distress signal was received.