Russian officials maintain, it is too early to know what caused a passenger jet to break apart and crash in Egypt on the weekend.

They are challenging an earlier comment from an airline executive who ruled out technical or mechanical problems.

Kogalymavia Flight 9268 broke into pieces before it hit the ground in a remote area of Egypt’s restive Sinai Peninsula on Saturday, killing all 224 people on board.

Kogalymavia airline official Alexander Smirnov told reporters in Moscow that the protection systems on the plane would have prevented it from crashing, even if there were major errors in the pilot’s control equipment.

“Therefore the only reason that could explain the plane’s breaking up in the midair can be a certain impact, purely mechanical (and/or) physical impact on (the) flying vessel,” he said.

The vague comment made translation difficult, with some interpreting that the executive said an “external influence” caused the crash.

The head of the Russian Federal Air Transport Agency, however, quickly pushed back.

“It is completely premature to speak about the reasons of this, as there are not grounds. And I’d like to call on the aviation community to refrain from any premature conclusions,” Transport Agency chief Alexander Neradko told the state-run Russian news agency Sputniknews.com.

Experts agree it is too early to know for certain what caused the plane to break up at the start of what could be a lengthy investigation.

CNN aviation correspondent Richard Quest suggested that the Kogalymavia official could have meant something abnormal and out of the ordinary had occurred.

However, Smirnov said that while the plane’s flight and voice data recorders had been recovered, they had not been read or decoded.

Officials have played down an apparent claim by Islamic militants in Sinai that they brought down the Airbus A321-200, saying technical failure is the most likely reason for the crash.

(CNN)