KUALA LUMPUR, Malaysia -- The missing Malaysian jetliner may have attempted to turn back before it vanished from radar, but there is no evidence it reached the Strait of Malacca, the country's air force chief said, denying reported remarks he said otherwise.
The statement suggested continued confusion over where the Boeing 777 might have ended up, more than four days after it disappeared en route to Beijing from Kuala Lumpur with 239 people on board.
The Malaysian military has radar data showing the missing jetliner changed course and made it to the Malacca Strait, hundreds of miles from the last position recorded by civilian authorities, according to a senior military official.
Malaysian Flight 370 was last detected flying over a small island known as Pulau Perak hundreds of miles from the flight's usual route from Kuala Lumpur to Beijing, according to the senior Malaysian Air Force official.
The development injects more mystery into the investigation of the disappearance of Saturday's flight, and raises questions about why the aircraft was not transmitting signals detectable by civilian radar.
With no debris found yet, authorities have not ruled out any possible cause, including mechanical failure, pilot error, sabotage or terrorism.
Local newspaper Berita Harian quoted Malaysian air force chief Gen. Rodzali Daud as saying radar at a military base had detected the airliner at 2:40 a.m. near Pulau Perak at the northern approach to the strait, a busy waterway that separates the western coast of Malaysia and Indonesia's Sumatra island.
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"After that, the signal from the plane was lost," he was quoted as saying.
A high-ranking military official involved in the investigation confirmed the report and also said the plane was believed to be flying low. The official spoke on condition of anonymity because of the sensitivity of the information.
Authorities had earlier said the plane, which took off from Kuala Lumpur on the western coast of Malaysia at 12:40 a.m. Saturday en route to Beijing, may have attempted to turn back, but they expressed surprise that it would do so without informing ground control.
The search for the plane was initially focused on waters between the eastern coast of Malaysia and Vietnam, the position where aviation authorities last tracked it. No trace of the plane, which was carrying 239 people, has been found by more than 40 planes and ships from at least 10 nations searching the area.
Earlier Tuesday, Malaysia Airlines said in a statement that search and rescue teams had expanded their scope to the Malacca Strait. An earlier statement said the western coast of Malaysia was "now the focus," but the airline subsequently said that phrase was an oversight. It didn't elaborate. Civil aviation chief Azharuddin Abdul Rahman said the search remained "on both sides" of the country.
Also Tuesday, authorities said two people who boarded the flight using stolen passports were Iranians who had purchased tickets to Europe. Their use of stolen documents had raised speculation of a possible terrorist link.
Malaysian police chief Khalid Abu Bakar said investigators had determined one 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," Khalid said.
Interpol identified the second man as Seyed Mohammed Reza Delavar, a 29-year-old Iranian, and released an image of the two boarding a plane at the same time. Interpol Secretary General Ronald K. Noble said the two men traveled 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." He appealed to the public for more information about them.
Noble said neither of the men had a criminal record.
Malaysia Airlines, meanwhile, said it is investigating an Australian television report that the co-pilot on the missing plane had invited two women into the cockpit during a flight two years ago.
Jonti Roos described the encounter on Australia's "A Current Affair." The airline said it wouldn't comment until its investigation is complete.
Roos said she and her friend were allowed to stay in the cockpit during the entire one-hour flight on Dec. 14, 2011, from Phuket, Thailand, to Kuala Lumpur. She said the arrangement did not seem unusual to the plane's crew.
"Throughout the entire flight, they were talking to us and they were actually smoking throughout the flight," Roos said.
Roos didn't immediately reply to a message sent to her via Facebook.
WCPO contributed to this report