The missing Malaysia Airlines jetliner had its communication systems disabled and was deliberately flown off course, Malaysian Prime Minister Najib Razak said Saturday.
At a press conference, Razak said there is a "high degree of certainty" that the data reporting system of Malaysia Airlines flight MH370 was disabled just before it reached the east coast of Malaysia. After which, he said the plane flew in a westerly direction back over the Malaysian peninsula before turning northwest until the point at which it left military primary radar coverage.
"These movements are consistent with the deliberate action by someone on the plane," Razak said.
As such, Malaysian authorities have refocused the investigation into the crew and passengers on board.
Despite media reports that the plane - carrying 227 passengers and 12 crew members from Kuala Lumpur to Beijing - was hijacked, he said authorities are still investigating all possibilities as to what caused the flight to deviate from its original flight path.
(Read more: Missing MH370: Timeline of latest developments)
The last confirmed communication between the plane and a satellite was at 8:11a.m. Malaysian time, he said, more than six hours after it vanished from civilian radar around 1:30 a.m. on March 8 without a distress call.
"The investigation team is making further calculations – which will indicate how far the aircraft may have flown after the last point of contact. Due to the type of satellite data, we are unable to confirm the precise location of the plane when it last made contact with a satellite," he said.
However, Razak said the investigators believe the aircraft is likely to be in one of two "corridors": north from the border of Kazakhstan and Turkmenistan through to northern Thailand, or south from Indonesia to the southern Indian Ocean.