Not ruling out the possibility of a hijack, Malaysia on Saturday said the movement of the missing flight MH370, with 239 people on board, was "consistent with deliberate action by someone on the plane".
Prime Minister Najib Razak said authorities are now trying to trace the plane across two possible corridors -- in the north to the border of Kazakhstan and Turkmenistan and a southern corridor from Indonesia to the southern Indian Ocean.
"Based on new satellite communication, we can say with a high degree of certainty that the aircraft communication addressing system was disabled just before the aircraft reached the east coast of Malaysia," Najib told reporters at a press conference.
He said the aircraft's transponder was switched off shortly afterwards while the plane was between the border of Malaysian and Vietnamese air traffic control.
"Radar data showed that from this point onwards, a plane believed to be MH370 did turn back and turned back in a westerly direction before turning north-west. These were deliberate actions of someone on the plane," he said, but stopped short of saying the aircraft had been hijacked.
"The last satellite communication was at 8.11 am (local time) on March 8," he said, suggesting that the plane was in the air for 7.5 hours after it lost communication.
The plane had left Kuala Lumpur for Beijing at 12.41 am and lost contact with civilian radar an hour later.
"Despite the media reports about hijacking, I am very clear we are still looking into all possibilities," he said.
The prime minister said that based on the raw satellite radar, it could be confirmed that the aircraft which was spotted an hour after it vanished from the civilian radar and was seen on the military's primary radar was indeed the missing Malaysian plane Boeing 777 Flight MH370.
Najib said investigators will again focus on the crew members and passengers.
"Clearly the search for MH370 has entered a new phase," he said. "We hope this new information brings us one step closer to finding the plane."
He said, "We are ending our operation in the South China Sea and reassessing the deployment of our assets."
There has been neither any trace of the plane nor any sign of wreckage despite a search by the navies and military aircraft of 14 countries across Southeast Asia that involves 43 ships and 58 aircraft.
Image: A woman writes a message expressing hope for the family members of passengers on board the missing Malaysia Airlines flight MH370 in a Buddhist temple in Subang Jaya, outside Kuala Lumpur ' Image: Samsul Said/Reuters