Russian, Egyptian governments split in Metrojet investigation

Four days into the investigation of the Metrojet airliner that crashed in the Sinai Peninsula on Saturday, it's still unclear if foul play was involved.

Forensic experts say victims of the crash suffered two different types of "explosive" trauma: Some passengers in front of the plane suffered severe burns and passengers in the tail end of the plane had metal pieces in their bodies, pointing to signs of an explosion.

New data also revealed the plane reached 31,000 feet before abruptly slowing down and then plummeting toward the ground at 300mph — data consistent with a sudden, catastrophic incident that stopped the plane in its tracks. Though the reason — mechanical error, sudden explosion or external impact — is still unclear.

See the wreckage of the plane crash in Egypt:

Investigators from both Egypt and Russia are examining the plane's black boxes.

A Russian news agency reported that a cockpit recorder picked up sounds of chaos in the flight's final 26 seconds in air, but the pilots didn't have enough time to send a distress signal.

The Russian airline said on Monday that the tragedy could not have been the result of technical or pilot error.

But officials in Cairo say there was no evidence to support claims by Russian officials that the airliner "broke up in the air." Both governments are at odds in the investigation.

Russia says the search zone for the Metrojet plane has been expanded for 15 square miles.

As of Wednesday morning, 33 of the 224 bodies have so far been identified.

PHOTOS: Russia mourns the 224 victims

More from AOL.com:
Ohio votes down legalizing pot for medical, recreational use
Republicans ask IRS to audit Clinton charity's finances
A mesmerizing NASA video shows sun in intimate detail