AKIPRESS.COM - Russia is suspending flights to and from Egypt until investigators determine what caused a Russian passenger jet to explode mid-air last weekend, The Courier Mail reports quoting the Kremlin.

"This concerns all flights," spokesman Dmitry Peskov told reporters.

Russian President Vladimir Putin ordered his government to halt the flights upon the recommendation of Russia's National Anti-Terrorism Committee, Peskov told reporters.

"So long as we have not established the true causes of what happened, I think it would be reasonable to stop Russian flights to Egypt," said Alexander Bortnikov, the head of Russia's Federal Security Service.

Metrojet Flight 9268 crashed in Egypt's Sinai Peninsula on Saturday, killing all 224 people on board.

An affiliate of the Islamic State extremist group claimed responsibility for the tragedy – the deadliest civil aviation disaster in Russian history.

There are two main theories for the disaster: a bomb placed on the Airbus A321 exploded, or a part of the 18-year-old plane's fuselage that was damaged more than a decade earlier succumbed to the cabin pressurisation and ripped apart.

The sound of an explosion could be heard on the black boxes recovered from the plane, according to an investigator who had access to them, French TV station France 2 said on its website. The investigator ruled out engine failure, it added.

British and U.S. spies intercepted "chatter" from suspected militants as well as internal communication about the incident from one other government that suggested a bomb, possibly hidden in luggage in the hold, had downed the airliner, intelligence sources said.

The intelligence sources, who spoke on customary condition of anonymity, said the evidence was not categorical and there was still no hard forensic or scientific evidence to support the bomb theory.

Britain suspended flights from Sharm el-Sheikh on Wednesday after the government said a bomb was the most likely cause of the crash.

Russian investigators took wipe samples from all the fragments of the jet and luggage to check for traces of explosives, the head of Russia's emergency services ministry said.

"The samples have been brought to Moscow and are being examined," said Vladimir Puchkov.

Russian authorities have been hesitant to endorse any theory for the cause of the crash ahead of official results from the investigation.