"With a high degree of certainty," authorities can say that MH 370's communication systems were disabled, Malaysia's Prime Minister Najib Rahman said Saturday. The airplane's transponder was also deliberately switched off.

The evidence is consistent with someone acting deliberately from inside the plane, Rahman said. Investigators have refocused their attention onto the pilots and passengers on board Flight MH 370, he said.

NBC News is reporting that Rahman said the search for the missing jet has widened to two corridors, including Kazakhstan-Turkmenistan border area and Indonesia to southern India.

Multiple news organizations are reporting Saturday that investigators have decided that one or more people with significant flying experience hijacked the missing Malaysia Airlines jet, switched off communication devices and steered it off-course, a Malaysian government official involved in the investigation told the Associated Press.

That same official told the Los Angeles Times that no motive has been established and it is not yet clear where the plane was taken. The official talked to news organizations on condition of anonymity because he was not authorized to brief the media.

He told the Associated Press the hijacking was no longer a theory.

“It is conclusive,” he said.

The LA Times reports that the Boeing 777's communication with the ground was severed just under one hour into a flight March 8 from Kuala Lumpur to Beijing. Malaysian officials have said radar data suggest it may have turned back toward and crossed over the Malaysian peninsula after setting out on a northeastern path toward the Chinese capital.

The Malaysian official said evidence that led to the conclusion were signs that the plane’s communications were switched off deliberately, data about the flight path and indications the plane was steered in a way to avoid detection by radar.

The Malaysian official said only a skilled aviator could navigate the plane the way it was flown after its last confirmed location over the South China Sea.

Why anyone would want to do this is unclear. Malaysian authorities and others will be urgently investigating the backgrounds of the two pilots and 10 crew members, as well the 227 passengers on board.

Some experts have said that piracy or pilot suicide may be the most likely explanation for the disappearance, as was suspected in a SilkAir crash during a flight from Singapore to Jakarta in 1997 and an EgyptAir flight in 1999.

The plane had enough fuel to fly for at least five hours after its last know location, meaning a vast swath of South and Southeast Asia would be within its reach. Investigators are analyzing radar and satellite data from around the region to try and pinpoint its final location, something that will be vital to hopes of finding the plane, and answering the mystery of what happened to it.

A U.S. official said Friday in Washington that investigators were examining the possibility of "human intervention" in the plane's disappearance, adding it may have been "an act of piracy." The official, who wasn't authorized to talk to the media and spoke on condition of anonymity, said it also was possible the plane may have landed somewhere.

CBS News reports that scores of aircraft and ships from 12 countries are involved in the search, which reaches into the eastern stretches of the South China Sea and on the western side of the Malay Peninsula, northwest into the Andaman Sea and the Indian Ocean.
CBS News national security correspondent David Martin reports that the USS Kidd has been assigned a search area in the Andaman Sea both east and west of the Andaman Islands. The P-8, which was scheduled to fly its first mission Friday tonight, will cover a grid that stretches west to the southern part of the Bay of Bengal.

India said it was using heat sensors on flights over hundreds of Andaman Sea islands Friday and would expand the search for the missing jet farther west into the Bay of Bengal, about 1,000 miles to the west of the plane's last known position.

A team of five U.S. officials with air traffic control and radar expertise - three from the U.S. National Transportation Safety Board and two from the Federal Aviation Administration - has been in Kuala Lumpur since Monday to assist with the investigation.