According to a Reuters report, investigators are now "90% sure that a bomb brought down the Russian Metrojet passenger plane in Egypt.

Investigators of the Russian plane crash in Egypt are "90 percent sure" the noise heard in the final second of a cockpit recording was an explosion caused by a bomb, a member of the investigation team told Reuters on Sunday.

The Airbus (AIR.PA) A321 crashed 23 minutes after taking off from the Sharm al-Sheikh tourist resort eight days ago, killing all 224 passengers and crew. Islamic State militants fighting Egyptian security forces in Sinai said they brought it down.

"The indications and analysis so far of the sound on the black box indicate it was a bomb," said the Egyptian investigation team member, who asked not to be named due to sensitivities. "We are 90 percent sure it was a bomb."

His comments reflect a higher degree of certainty about the cause of the crash than the investigation committee has so far declared in public.

Lead investigator Ayman al-Muqaddam announced on Saturday that the plane appeared to have broken up in mid-air while it was being flown on auto-pilot, and that a noise had been heard in the last second of the cockpit recording. But he said it was too soon to draw conclusions about why the plane crashed.

Confirmation that militants brought down the airliner could have a devastating impact on Egypt's lucrative tourist industry, which has suffered from years of political turmoil and was hit last week when Russia, Turkey and several European countries suspended flights to Sharm al-Sheikh and other destinations.

It could also mark a new strategy by the hardline Islamic State group which holds large parts of Syria and Iraq.

British authorities arer hot on the trail of the men they believe mmay have had a hand in building the bomb that brought the plane down.

BRITISH extremists were behind the bombing of a Russian jet over Egypt, intelligence experts believe.

They were overheard celebrating moments after the explosion that blew the plane apart, killing all 224 on board.

The jihadis were heard talking in Birmingham and London accents by spies at GCHQ in Cheltenham.

Trained in Syria and with an electronics background, it is believed they may have had a hand in building the bomb.

The success of the attack could inspire them to target British airports next, a former Special Branch officer warned last night.

GCHQ, the Government’s secret listening centre, picked up “chatter” from extremist groups in Egypt immediately after the Russian plane came down.

The regional accents suggest “a definite and strong link” between British extremists and the attack, according to intelligence sources.

“Jihadis in the Sinai area of Egypt could be heard celebrating,” one source said yesterday.

“A closer analysis of that material has identified London and Birmingham accents among those numerous voices.

“There has also been some internet traffic suggesting that there was British involvement in the attack. This was a very sophisticated, carefully planned operation involving many moving parts.

“We know there are British jihadis in Egypt fighting with members of Islamic State. They were trained in Syria and are now hardened terrorists. Some of the Britons have an electronics background and have been developing some very sophisticated bombs.

“They have been experimenting with different-sized charges and different types of explosives but there was nothing prior to this attack to suggest that they were going after airlines.” 

And so it begins - the wave of terror attacks carried out by European Muslims who went to Syria to join Islamic State. There are thousands of them - many of whom have returned home. How many were in the million refugees who have forced their way into Europe only to disappear?

Unless we're luckier than we deserve to be, the West is about to live out a painful lesson in taking Islamic terrorism as seriously as the terrorists themselves are about killing us.