KUALA LUMPUR, Malaysia -- The missing Boeing 777 jetliner changed course over the sea, crossed Malaysia and reached the Strait of Malacca, hundreds of miles from its last position as recorded by civilian authorities, Malaysian military officials said Tuesday, citing military radar data.
The development added confusion and mystery into one of most puzzling aviation incidents of recent time, and it has raised questions about why the Malaysia Airlines flight apparently was not transmitting signals detectable by civilian radar, why its crew was silent about the course change, and why no distress calls were sent after it turned back.
Many experts have been working on the assumption that there was a catastrophic event on the flight -- such as an explosion, engine failure, terrorist attack, extreme turbulence, pilot error or even suicide. CIA director John Brennan said in Washington that he still would not rule out terrorism.
Flight MH370, carrying 239 people, took off for Beijing from Kuala Lumpur at 12:41 a.m. local time Saturday. Authorities initially said its last contact with ground controllers was less than an hour into the flight, at a height of 35,000 feet, when the plane was somewhere between Malaysia's east coast and Vietnam.
But local newspaper Berita Harian quoted Malaysia's air force chief, Gen. Rodzali Daud, as saying radar at a military base had tracked the jet as it changed course, with the final signal at 2:40 a.m. showing it near Pulau Perak at the northern approach to the Strait of Malacca, a busy waterway that separates Malaysia's western coast and Indonesia's Sumatra island. It was flying slightly lower, at around 29,528 feet, he said. "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. The official spoke on condition of anonymity because he was not authorized to disclose sensitive information. Authorities earlier had said the plane may have tried to turn back to Kuala Lumpur but expressed surprise that it would do so without informing ground control.
The search was initially focused hundreds of miles to the east, in waters off Vietnam, with more than 40 planes and ships from at least 10 nations searching the area without finding a trace of the missing aircraft.
Earlier Tuesday, Malaysia Airlines said in a statement that search-and-rescue teams had expanded their scope to the Strait of Malacca.
Attention will likely focus on the condition of the Boeing 777's electronic systems as it charted its new course back toward and then across Malaysia.
A radar antenna on the ground sends electromagnetic waves that reflect from the surface of an aircraft and almost instantly return, letting controllers calculate how far away a plane is. The antenna is mounted on a rotating platform, sending and receiving signals 360 degrees across the sky, enabling the plane's direction to be tracked by constant sweeps.
The system has limitations: Military and civilian air traffic controllers know something is moving through the air, but might not know what it is. So planes were outfitted with transponders that can send a unique signal back to the radar station, which can then differentiate them from other aircraft. From this signal, controllers can tell the flight number, heading, speed and altitude.
Malaysian police chief Khalid Abu Bakar, who has been ordered to look at possible criminal aspects in the disappearance of Flight MH370, said hijacking, sabotage and issues related to the pilots' psychological health were all being considered.
An Australian TV station reported that the first officer on the missing plane, Fariq Abdul Hamid, had invited two women into the cockpit during a flight two years ago. One of the women, Jonti Roos, described the encounter on Australia's "A Current Affair." Ms. Roos said she and a 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.
Also Tuesday, Malaysian and international police authorities said two people who boarded Flight MH370 with stolen passports were Iranians who had bought tickets to Europe, where they were planning to migrate. Their presence on the flight had raised speculation of a possible terrorist link.
Malaysian police chief Khalid Abu Bakar said investigators had determined that one was a 19-year-old Iranian, Pouria Nourmohammadi Mehrdad. "We believe he is not likely to be a member of any terrorist group," Chief 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 at the same time. Interpol Secretary-General Ronald Noble said the two men traveled to Malaysia on their Iranian passports, then apparently switched to their stolen Austrian and Italian documents.