KUALA LUMPUR/Washington  - Intelligence checks on 153 Chinese passengers on a missing Malaysian airliner produced no red flags, China said Tuesday, as Malaysia marshalled ships and planes from 26 countries to search an area the size of Australia.

Eleven days after contact was lost with Malaysia Airlines Flight 370 and its 239 passengers and crew, there has been minimal progress in determining precisely what happened or where the plane ended up. Lending fresh weight to the belief that the plane was deliberately diverted, the New York Times reported that the first turn it made off its flight path was programmed into the Boeing 777’s computer navigation system, probably by someone in the cockpit.

Rather than manually operating the plane’s controls, whoever altered Flight 370’s path typed seven or eight keystrokes into a computer situated between the captain and the co-pilot, the newspaper said, quoting US officials. The head of Malaysia Airlines, Ahmad Jauhari Yahya, said he was unable to confirm the report.

‘The aircraft was programmed to fly to Beijing but once you are in the aircraft, anything is possible,’ he told a daily press briefing. Two thirds of those on board were Chinese and Malaysia had asked authorities in Beijing to run an exhaustive background check on all their nationals as part of a probe into everyone aboard.

On Tuesday China’s ambassador to Malaysia Huang Huikang said no evidence had been found that would link anyone to a possible hijacking or terrorist attack on the jet. The current search area, which was only properly identified after a week of fruitlessly scouring the South China Sea, is enormous - stretching from the depths of the Indian Ocean, up and over the Himalayas and into central Asia. Transport Minister Hishammuddin Hussein said it covered a total of 2.24 million square nautical miles (7.7 million square kilometres) - slightly larger than Australia. China’s state media has been vocally critical of Malaysia’s handling of the investigation, saying valuable time and resources were wasted in the hours and days immediately after the aircraft disappeared on March 8.

Desperate relatives of the Chinese passengers threatened to go on hunger strike Tuesday, demanding that Malaysia’s ambassador brief them in person. Malaysian officials insist they are investigating all the passengers and crew but for the moment the focus is clearly on the two pilots - Captain Zaharie Ahmad Shah and First Officer Fariq Abdul Hamid. On Monday Ahmad Jauhari revealed that the last recorded words from the cockpit - ‘All right, good night’ - were almost certainly spoken by the co-pilot, Fariq. The identity was deemed important given that the final message came around the time the plane’s two automated signalling systems were disabled and it veered off course just as it was being handed over from Malaysian to Vietnamese air traffic control.

Despite some confusion about when the systems were switched off, Hishammuddin stressed that investigators still believe the series of events were consistent with ‘deliberate action’ by someone on the plane. The nonchalant style of the verbal sign-off had been queried in some quarters but a Boeing 777 pilot told AFP it was ‘completely normal’ for a pilot leaving his domestic air space. Police have searched both pilots’ homes and are examining a flight simulator that Captain Zaharie, 53, had assembled at his home.

Malaysian media reported that Zaharie was distantly related to the daughter-in-law of opposition leader Anwar Ibrahim, as well as being a member of his political party. Anwar said Tuesday he was ‘disgusted’ by the suggestion the plane may have been sabotaged as an act of revenge hours after he was convicted on a sodomy charge widely seen as politically motivated. Hishamm-ud-Din said the search for the missing aircraft should remain ‘above politics’.

Twenty-six countries are now involved in that search in a northern corridor over south and central Asia and a southern corridor stretching deep into the southern Indian Ocean towards Australia. A French expert who took part in the search for Air France Flight 447, which crashed in the Atlantic in 2009, said finding the Malaysian plane was a much tougher proposition. ‘Here we simply have no idea of the location of the aircraft because there were no Acars signals,’ said Jean-Paul Troadec, a special adviser with France’s civil aviation accident investigation agency.

Malaysia has deployed its navy and air force to the southern corridor where Australia is taking the lead in scouring a huge section of ocean off its west coast. ‘It will take at least a few weeks to search the area thoroughly,’ said John Young of the Australian Maritime Safety Authority. The US Pacific Fleet withdrew a guided missile destroyer, saying the area was simply too big for such a vessel to make an effective contribution. ‘The Indian Ocean goes so far, there probably aren’t enough ships and aircraft in the world to search every inch of it,’ Fleet spokesman Commander William Marks told CNN.

Desperate relatives of Chinese passengers aboard flight MH370 threatened to go on hunger strike as they demanded answers about the missing aircraft from Malaysian officials. ‘Now we have no news and everyone is understandably worried. The relatives say they will go to the Malaysian embassy to find the ambassador,’ said Wen Wancheng, whose son was aboard the missing flight. ‘The Malaysian ambassador should be presenting himself here. But he’s not,’ Wen said, updating reporters after a regular meeting between Malaysia Airlines officials and family members at a hotel in Beijing.

‘Relatives are very unsatisfied. So you hear them saying ‘hunger strike’,’ added the 63-year-old from the eastern province of Shandong, speaking as the search entered its 11th day. Outside the meeting room, a woman clutching a placard reading ‘Respect life. Give us back our families” told reporters that the relatives were going on hunger strike. She declined to say how many were doing so, or give her name.

‘Since they haven’t given us the truth about those people’s lives, all of us are protesting,” the woman said furiously. ‘All the relatives are facing mental breakdowns,’ she added. Wen also said some of the relatives had stopped going to the meetings, given how long they had been waiting for information. ‘It doesn’t mean giving up,” he added. “It’s normal to return home. Like me, I have been out for a long time.’ A poem was hung on a wall directly outside the relatives briefing room, credited to “Xue Song”, although it was not clear whether it was put up by a family member. “On Malaysia Airlines our relatives have ridden, we don’t know where the plane is hidden,” said the poem.

“The Malaysian spokesman statements make us guess, and turn the search into a great big mess. “Let down, accusing and deep frustration, our families are left in desolation. “We just long to meet one more time, counting seconds flowing like tears in a line.” Beijing has been critical of Malaysia’s sharing of information, with state media and China’s huge army of netizens in expressing anger at the handling of the incident by Kuala Lumpur.

The turn that diverted the missing Malaysian Airlines plane off its flight path was programmed into the aircraft’s computer navigation system, probably by someone in the cockpit, the New York Times reported late Monday. That reinforces the increasing belief among investigators that the aircraft was deliberately diverted, the newspaper said, quoting US officials. Rather than manually operating the plane’s controls, whoever altered Flight 370’s path typed seven or eight keystrokes into a computer situated between the captain and the co-pilot, according to officials.

The computer is called the Flight Management System. It directs the plane from point to point specified in the flight plan submitted before a flight. It is not clear whether the plane’s path was reprogrammed before or after it took off, the Times said. Flight 370 vanished on March 8 with 239 people aboard a flight from Kuala Lumpur to Beijing.

Malaysia said Saturday it believed the plane had been diverted because its transponder and other communications devices had been manually turned off several minutes apart. But confusion has taken hold over the timeline of events before ground controllers lost contact with the aircraft. Malaysia on Monday said it was the co-pilot Fariq Abdul Hamid who was the last person in the cockpit to speak to ground control. Identifying the voice had been deemed crucial because officials initially said the words were spoken after one of the Boeing’s two automated signalling systems - Aircraft Communications Addressing and Reporting System (ACARS) - had been manually disabled.

But Malaysia Airlines director Ahmad Jauhari Yahya contradicted that chronology, saying that the ACARS could have been switched off before or after Fariq spoke. The Times said the changes made to the plane’s direction through the Flight Management System were reported back to a maintenance base by ACARS, according to an American official.

A US naval ship that has been aiding the international search for a missing Malaysian airliner will be withdrawn from the effort, Pentagon officials said Monday. After taking off from Kuala Lumpur headed to Beijing, Malaysia Airlines Flight 370 disappeared on March 8 with 239 people on board, triggering a massive international search across Southeast Asia and the Indian Ocean. The New York Times, citing American officials, said separately Monday that the first turn to the west that diverted the plane from its planned flight path was carried out through a computer system that was most likely programmed by someone in the cockpit.