The chairman of the Egyptian-led investigation into the Russian airliner that crashed in the Sinai peninsula said on Saturday that an unknown noise can be heard on the plane's black box recordings moments before the crash, but the evidence is not enough to conclusively determine the cause of the disaster.
Ayman al-Muqaddam of the Egyptian government's Aviation Incidents Committee told reporters that investigators will conduct "a spectral analysis" to identify "the nature of the noise." He said, however, that preliminary evidence indicates an "in-flight breakup."
There have been multiple reports over the past week citing intelligence officials and others as saying a bomb likely brought down the plane. Without ever using the word "bomb," al-Muqaddam said the Egyptian-led team, which includes investigators from Russia, France, Ireland, and Germany, was not privy to those details and could not confirm or deny the reports.
"The committee noted in their reports and analysis, some of which claimed to be based on official intelligence which favors a certain scenario for the cause of the accident," Al-Muqaddam said. "The committee was not provided with any information or evidence in this regard. The committee urged the sources of such reports to provide it with all information that could help us to undertake our mission."
On Friday, French officials who have heard the black box recording of the Russian airliner that crashed in Egypt said that it indicated a "violent and sudden demise." At the same time, anonymous British intelligence officials confirmed that they intercepted chatter before the crash that suggested the Islamic State was involved.
The Russian airliner crashed last Saturday en route from Sharm El-Sheikh to St. Petersburg, killing all 224 people on board. A French official close to the investigation told AFP, "Everything was normal during the flight, absolutely normal, and suddenly there was nothing."
Al-Muqaddam said the the black box recording from the plane lasts 23 minutes and 14 seconds after takeoff. He said debris from the crash is scattered over an area nearly 13 kilometers wide in the central Sinai desert, and that bad weather in recent days has hampered the investigation. He also noted that some pieces of wreckage are still missing.
On Wednesday, the Islamic State's Sinai affiliate — Ansar Bait al-Maqdis — took credit for taking down the plane, but provided few details of the purported plot.
Since the Islamic State does not possess the surface-to-air missiles capable of shooting down a jetliner at cruising altitude, speculation has centered on the possibility of an on-board bomb.
The Russian and Egyptian governments initially rejected the suggestion that the incident was related to terrorism.
Egyptian President Abdel Fattah al-Sisi forcefully rebuffed reports of Islamic State involvement. "'When there is propaganda that it crashed because of ISIS, this is one way to damage the stability and security of Egypt and the image of Egypt," Sisi said on Tuesday, using a common abbreviation for the militant group's name.
Then on Wednesday, a US official confirmed to CNN that early evidence indicated the plane was brought down by a bomb. President Barack Obama also said the US was "seriously considering" the possibility that a bombing was to blame.
The office of British Prime Minister David Cameron said on Thursday that the UK had information that suggested the cause of the crash "was more likely than not a terrorist bomb."
The Egyptians fired back on Thursday, rejecting the US characterization. "The investigation team does not yet have any evidence or data confirming this hypothesis," said Hossam Kamal, Egypt's minister for civil aviation.
The UK suspended all flights between Sharm El-Sheikh and Britain after sending a team of investigators to evaluate security measures at the resort town's airport. On Friday, the UK began to evacuate passengers from the resort city.
Throughout the week, Kamal and the Egyptian government have repeatedly insisted that Egyptian airport security was "up to international standards." But VICE News spoke to several travelers who had passed through the Sharm El-Sheikh airport over the past month, and all reported lax security.
"When I went through, two guys were talking next to the machine and nobody was looking at the monitor," one traveler who wished not to be identified said. "People were just walking straight through with liquid, they weren't stopping anyone."