The strait is hundreds of miles away from the last location reported by civilian authorities and the development injects new mystery into the investigation of the flight’s disappearance. Local newspaper Berita Harian yesterday quoted Malaysian air force chief General Rodzali Daud as saying radar at a military base had detected the airliner near Pulau Perak, at the northern approach to the strait.
A high-ranking military official involved in the investigation confirmed the report and also said the aircraft, with 239 people on board, was believed to be flying low. Earlier, it emerged two men travelling with stolen passports on a missing Malaysia Airlines plane were Iranians who had bought tickets to Europe and were probably not terrorists, according to officials.
The announcement is likely to dampen speculation the disappearance of the Boeing 777 was linked to terrorism. Police said both men bought their tickets in Thailand and entered Malaysia together.
No debris from the plane has been found, experts said last night. Authorities have expanded their search to the opposite side of Malaysia from where the aircraft disappeared more than four days ago.
The airline says the pilots did not send any distress signals, suggesting a sudden and possibly catastrophic incident.
Speculation has ranged widely about possible causes, including pilot error, plane malfunction, hijacking and terrorism.
Malaysian police chief Khalid Abu Bakar told a news conference that investigators had determined one of the men who used a stolen passport was a 19-year-old Iranian, Pouria Nourmohammadi Mehrdad, and that it seemed likely he was planning to migrate to Germany.
“We believe he is not likely to be a member of any terrorist group,” Mr Khalid said.
Interpol identified the second man as a 29-year-old Iranian – also thought to be an asylum seeker – and released an image of the two boarding a plane at the same time.
Interpol secretary general Ronald K Noble said the two men travelled to Malaysia on their Iranian passports, then apparently switched to their stolen Austrian and Italian documents.
He said speculation of terrorism appeared to be dying down “as the belief becomes more certain that these two individuals were probably not terrorists”.
Mr Khalid said the 19-year-old man’s mother was waiting for him in Frankfurt and had been in contact with police. He said she contacted Malaysian authorities to inform them of her concern when her son did not get in touch with her.
The plane took off from Kuala Lumpur, on the western coast of Malaysia, early on Saturday en route to Beijing. It flew across Malaysia into the Gulf of Thailand at 35,000ft, then disappeared from radar screens.
Authorities said the plane may have attempted to turn back towards Kuala Lumpur.
The hunt for the plane began near the plane’s last-known location. But with no debris found there, the search has been systematically expanded to include areas the plane could have reached with the fuel it had on board – a vast area in which to locate something as small as a piece of an aircraft.
Malaysia Airlines said search and rescue teams have expanded the scope beyond the flight path to the Straits of Malacca between Malaysia’s western coast and Indonesia’s Sumatra island – the opposite side of Malaysia from its last-known location.
An earlier statement said the western coast of Malaysia was “now the focus”, but the airline subsequently said that phrase was an oversight.
“The search is on both sides,” civil aviation chief Azharuddin Abdul Rahman said.
The search currently includes nine aircraft and 24 ships from nine countries which have been scouring the Gulf of Thailand on the eastern side of Malaysia. Land areas also are being searched.
Assuming the plane crashed into the ocean or disintegrated in midair, there will likely still be debris floating in the ocean, but it may be widely spread out, and much may have already sunk. In past disasters, it has taken days or longer to find wreckage.
The United States has sent two navy ships, at least one of which is equipped with helicopters, and a Navy P-3C Orion plane with sensors that can detect small debris in the water. Vietnamese planes and ships are also taking part.
Lieutenant General Vo Van Tuan, deputy chief of staff of the Vietnamese People’s Army, said authorities on land had also been ordered to search for the plane, which could have crashed into mountains or uninhabited jungle. He said military units near the border with Laos and Cambodia had been instructed to search their regions also.
“So far we have found no signs … so we must widen our search,” he said.
In the US, CIA Director John Brennan said the possibility of a terror link could not be ruled out. But he said “no claims of responsibility” over the missing jet had “been confirmed or corroborated”.
“Clearly this is still a mystery, which is very disturbing,” he said at the Council on Foreign Relations think-tank
China, home to two-thirds of the passengers, urged Malaysian authorities to “speed up the efforts” to find the plane. It has sent four ships, with another four on the way. A shopping mall in Beijing suspended advertising on its large outdoor LED screen to display a search timer – an image of an plane along with a digital clock marking the time since contact with the flight was lost.
Relatives have expressed frustration at the lack of information about the plane’s fate.
Analysis by Tim Ripley: Technical problem could have led to the search being focused in the wrong area
Speculation has been rife about the fate of the Boeing 777 airliner and the 239 passengers and crew on board.
A huge air and sea search has failed to find any evidence to point to what has happened to the jet.
It is very difficult to hide a plane the size of Boeing 777 from satellite surveillance, and the lack of any demands from hijackers seems to suggest that the aircraft is not hidden away on a remote island airstrip.
If the aircraft did break up at high altitude, then a debris field should have been relatively easy to spot and the radio beacons inside the black box data recorder should have activated.
Other theories point to the aircraft diving into the sea at speed – but this also would have left wreckage on the surface.
The main theories for the incident revolve around either a catastrophic technical problem on board the jet, a terrorist bombing or a hijacking to an as yet unidentified location. There are serious questions to be asked about why the search and rescue forces have yet to find the aircraft.
Working out where to search is the key to finding such debris, and search authorities usually use a mathematical formula to project where debris will drop to earth, based on momentum and the wind speed in area of accident. This, however, depends on the authorities having accurate data to work from.
There are a number of reasons why the searchers might have so far been looking in the wrong place.
Firstly, radar coverage is patchy in the area and the Malaysia Airlines jet might have been in a “radar gap” at the time of its loss.
Secondly, air traffic control authorities rely on information broadcast from transponders on aircraft, which boost the performance of ground radar surveillance.
Transponders also help ground controllers positively identify any aircraft on cluttered radarscopes.
If there was a technical problem with the jet’s transponder, then air traffic control might have received erroneous data and diverted the rescue authorities to launch their initial searches in the wrong area. The widening of the search area yesterday signifies that the Malaysian authorities are reassessing all their previous assumptions about where MH370 came to rest.
• Tim Ripley is a UK-based defence analyst and aviation expert