BEIJING, March 15 -- Western media reports began to suggest Friday that Malaysia Airlines flight MH370 missing for nearly a week was deliberately flown hundreds of miles off course, deepening suspicions of piracy and foul play among investigators.

Analysis of Malaysian military data shows the plane diverted from its settled route and flew west, using airline flight corridors normally employed for routes to the Middle East and Europe, the Chicago Tribune quoted sources familiar with the investigations as saying.

This indicates that the plane was either being flown by the pilots or someone with knowledge of waypoints on the routes, said the source.

The latest evidence suggests the plane did not experience a catastrophic incident over the South China Sea. Some experts believed that one of the pilots or someone else with flying experience hijacked the plane or committed suicide by plunging the jet into the sea, the Associated Press said Friday.

Adding the speculation that someone was flying the aircraft, the New York Times on Friday quoted sources familiar with the investigation as saying that the plane experienced significant changes in altitude after losing contact with ground control, and altered its course more than once.

In another development, Inmarsat, a British satellite telecommunications company, said on Friday that its network had received signals from the missing flight.

In a very brief statement, Inmarsat said: "Routine, automated signals were registered on the Inmarsat network from Malaysia Airlines flight MH370 during its flight from Kuala Lumpur."

"This information was provided to our partner SITA, which in turn has shared it with Malaysia Airlines," the statement said.

BBC also reported on Friday that a satellite system operated by Inmarsat received an automated signal from flight MH370 at least five hours after the plane was reported lost.

That could mean that the plane may have been flying for more than five hours after it disappeared, according to the BBC report.

Xinhua contacted the London-based company, but Mario Lehmann, an official from Inmarsat declined to comment, saying the company has been listed as an independent investigator.

A classified analysis of electronic and satellite data conducted by the U.S. and Malaysian governments calculates that the missing flight likely crashed either in the Indian Ocean, or in the Bay of Bengal, according to a CNN report on Friday.

One flight path suggests the plane may have crashed into the Bay of Bengal off the coast of India, and the other it traveled southeast and crashed in the Indian Ocean, according to the analysis.

Yet another theory is taking shape about what might have happened to the missing plane: Maybe it landed in a remote Indian Ocean island chain, the report said.

The theory based on analysis of radar data revealed Friday suggests that the plane wasn't just blindly flying northwest from Malaysia, the report said.

Meanwhile, a U.S. Navy vessel and a surveillance aircraft have been en route to an expanded search area for the missing plane, including the Andaman Sea and the Bay of Bengal Friday.

"At Malaysia's request, the USS Kidd is north of the Strait of Malacca, in what we are calling the western search area," said Pentagon spokesman Army Col. Steven Warren on Friday.

For China's part, the China Maritime Search and Rescue Center said Friday that it will expand the search area for the missing jet in the coming days.

The search will be expanded to the east and west, with intensive search in the east region and enhanced efforts in the southeast from Saturday.

It will also augment logistics support and arrange search rotations of different vessels, said He Jianzhong, director of the center.

Eight Chinese vessels had searched 70,078 square km of the sea's surface as of 18 p.m. Friday, covering 6,846.3 square km of waters underneath. No confirmed debris has been found.

Flight MH370, a Boeing 777-200ER, suddenly disappeared from radar screen on its way to Beijing last Saturday shortly after taking off from Kuala Lumpur. The plane was carrying 227 passengers and 12 crew, including 154 Chinese.

So far, massive search and rescue operations have failed to find any trace of the plane.