KUALA LUMPUR, March 16 — Malaysian authorities’ failure to act sooner on now-confirmed details on the movements on Malaysia Airlines flight MH370 continues to baffle foreign investigators searching for the plane missing for over eight days.

Speaking to the New York Times, they were mystified that the Royal Malaysian Air Force (RMAF) did not respond to an apparent intrusion into the country’s air space by an unidentified aircraft that later flew over densely-populated areas including Penang.

Compounding the earlier error was the inability to verify until yesterday — one week after the Beijing-bound plane with 239 onboard — went missing that the plane it recorded flying across peninsular Malaysia was indeed MH370.

“The fact that it flew straight over Malaysia, without the Malaysian military identifying it, is just plain weird — not just weird, but also very damning and tragic,” David Learmount, the operations and safety editor for aviation news site Flightglobal, told the NYT.

The blunder caused a multinational search effort to focus the brunt of its resources in the South China Sea, where the plane stopped transmitting to ground control but also where it was now shown that the Boeing 777-200ER had only briefly flown over before it turned west again.

Following yesterday’s revelation by Malaysia, the weeklong search operation in area was ended.

Investigators added that had Malaysia sent a plane out to intercept the flight now established as MH370, search and rescue efforts might not have been as daunting as it has now become.

“The watch team never noticed the blip ... It was as though the airspace was his,” a source familiar with the MH370 investigation told the newspaper regarding the four-man radar crew in Butterworth.

RMAF chief Tan Sri Rodzali Daud conceded earlier in the week that MH370 was only recorded by the air force’s radar stations as it flew west across peninsular Malaysia, and that the incident was not observed as it happened.

Rodzali also said the military only paid heed to signatures that were considered “hostile”, which he said MH370 did not appear to be at the time.

Investigators also pointed out that Malaysia failed to search the homes of the pilots, captain Zaharie Ahmad Shah and first officer Fariq Abdul Hamid, despite saying it was investigating “all possibilities.”

Police only searched the homes of the two pilots yesterday, after Prime Minister Datuk Seri Najib Razak announced to the world that the disappearance of MH370 was due to “deliberate action”.

Aviation experts voiced belief early on that the complexity of the operation — manually disabling the plane’s Aircraft Communications Addressing and Reporting System and then, its transponder, before threading the plane through a series of radar-evading waypoints — pointed to the pilots.

It is unclear if anyone else had access to the homes prior to the police searches yesterday.

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.

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.