KUALA LUMPUR, March 16 — A possible series of “tactical evasion manoeuvres” by Malaysia Airlines flight MH370 to skirt radar zones is now increasing investigators’ scrutiny on the two pilots of the missing plane.

According to ABC News, law enforcement and intelligence agencies in the United States believe that the intricate flight pattern was meant to avoid detection by primary radar stations after the plane’s transponders were manually disabled and could only have been pulled off by an experienced aviator or a one with deep technical knowledge.

The news channel cited an official it did not name as saying that a study of the 239 onboard suggested that none beyond captain Zaharie Ahmad Shah, 53, and first officer Fariq Abdul Hamid, 27, have the necessary experience to pilot the plane in the way it was observed.

But it also conceded that one or both men may have acted under duress.

Yesterday, the police searched the homes of Zaharie and Fariq in Shah Alam shortly after Prime Minister Datuk Seri Najib Razak told a news conference that MH370 was diverted deliberately, after someone on board switched off the Boeing 777’s communications systems.

After it went dark in the early hours of March 8, the plane was then flown westward from its intended path to Beijing, turning around at Checkpoint Igari in the South China Sea.

From there, it flew on to Checkpoint Vampi, northeast of Indonesia’s Aceh province and a navigational point used for planes following route N571 to the Middle East.

Subsequent plots indicate the plane flew towards Checkpoint Gival, south of the Thai island of Phuket, and was last plotted heading northwest towards another checkpoint, Igrex, used for route P628 that would take it over the Andaman Islands and which carriers use to fly towards Europe.

Najib said yesterday investigation on the disappearance of MH370 will now refocus of the passengers and crew onboard.

Najib also said yesterday that the final satellite communication with the plane occurred at 8.11am on March 8, indicating it continued flying after its transponder was disabled and the engine performance data link with MAS was severed more than seven hours before. But the satellite data did not indicate the plane’s location at the time.

It was also confirmed that military radar definitively tracked MH370 as it changed course and headed west towards the Indian Ocean.

The prime minister said that search and rescue efforts in the South China Sea would be called off and pointed to two corridors where the plane could possibly be located: a northern arc from northern Thailand to the border of Kazakhstan and Turkmenistan in central Asia, or a southern one from Indonesia to the southern Indian Ocean.