Missing Malaysia Airlines flight MH370 changed course on its way from Kuala Lumpur to Beijing via the cockpit’s computerized Flight Management System, not by manual control, American officials suggested to the New York Times.

The officials said Monday that only seven or eight keystrokes would have been sufficient to change the Boeing 777’s flight path, though it was not clear whether the system was reprogrammed before or after takeoff.

Regardless, the theory supports the belief of investigators – first voiced by Malaysian officials – that the flight was deliberately diverted.

On Saturday, Malaysian Prime Minister Najib Razak said that investigators had reliable information that someone on the plane had “deliberately disabled” communications systems before the plane vanished. Furthermore, investigators said that it would have taken someone with pilot training to be able to switch off the Aircraft and Communications Addressing and Reporting System, or ACARS. This system automatically sends engine data and other information to the airline.

Yet Malaysian officials retracted the ACARS theory on Monday. They believe ACARS was still functioning when the plane’s co-pilot spoke the last words heard from MH370 by ground control.

ACARS lost function around the same time oral radio contact was cut off and as the airplane’s transponder halted, the Times reported.

Investigators are combing over radar tapes from MH370’s departure given they believe the recordings would show that after the plane changed its path, it went through several pre-ordained “waypoints,” or markers in the sky. That would implicate that a knowledgeable pilot was controlling MH370 as it went through those points, as passing through them without a computer is not likely.

One waypoint was added to MH370’s planned route, according to investigators. Pilots would do this if an air traffic controller orders a different route to avoid weather or traffic. Yet the wayward point in this case was well off the path to Beijing.

American officials said that if anyone changed the course of the flight by reprogramming the Flight Management System, it would likely be someone familiar with Boeing aircraft.

Meanwhile, China has started a search and rescue operation in a northern region of its own territory, Chinese Ambassador to Malaysia Huang Huikang said early Tuesday, according to Xinhua.

Indonesia and Australia said Monday they would divide between them a large section of the south-eastern Indian Ocean in the plane search. Indonesia will examine equatorial waters while Australia will focus farther south, according to the Times.

On Sunday, Pakistan became one of 25 countries participating in the search for the missing plane. UK newspaper The Independent reported that Malaysian investigators had requested permission from the Pakistani government to follow up on a theory that the missing passenger jet had landed close to the border with Afghanistan.

The Pakistani government says it has no record of the craft entering its airspace, but has told the Malaysian investigators it is ready to share all available information. In addition, The Kazakh Civil Aviation Committee has said that although the Malaysian Airlines plane could have reached Kazakhstan, their radars would have picked it up.

"No information about the Malaysian plane is available at our radar as it has not entered our airspace," Foreign Ministry spokesperson Tasnim Aslam told reporters when asked to comment on the Malaysian government's request. “Our radar system has no information about the Malaysian aircraft as it has never contacted our control tower.”