KUALA LUMPUR, Malaysia (AP) — The search for the missing Malaysian Airlines jet has pushed deep into the northern and southern hemispheres.

Australia is scouring the southern Indian Ocean while Kazakhstan, more than 6,000 miles) to the northwest, has answered Malaysia's call for help in the hunt.

Investigators say the Malaysia Airlines jet carrying 239 people was deliberately diverted and its communications equipment switched off.

Suspicion has fallen on the pilots because of their aviation experience, although Malaysian officials have said they are seeking background checks on everyone aboard the flight.

Malaysia Airlines believes it was the co-pilot aboard its missing plane who spoke the last words to ground controllers. The airline says initial investigations indicate that the co-pilot is the one who calmly said, "All right, good night."

Officials said previously that those words were spoken after the jetliner's data communications systems had been switched off. However, Malaysia Airlines' CEO says it remains unclear at what point the system was switched off.

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