The Daily Star's FREE newsletter is spectacular! Sign up today for the best stories straight to your inbox Sign up today! Thank you for subscribing See our privacy notice Invalid Email

(Image: AP)

Russian officials confirmed an ISIS bomb had blown up the plane, which crashed over the Sinai Peninsula in Egypt on October 31, killing all 224 people on board.

Putin has said Russian intelligence sources will find the masterminds behind the plot.

The Russian leader added: "It (our campaign) must be intensified in such a way that the criminals understand that retribution is inevitable.

"We will search for them everywhere wherever they are hiding. We will find them anywhere on the planet and punish them."

The MetroJet flight — operated by the small Russian airline Kogalymavia — disappeared from radar about 25 minutes after it took off from Sharm El-Sheikh airport.

Two Sharm El-Sheikh airport employees have so far been detained, suspected of aiding those who planted the bomb on the jet.

(Image: REUTERS)

An Egyptian authority official said: "Seventeen people are being held, two of them are suspected of helping whoever planted the bomb on the plane at Sharm al-Sheikh airport."

Traces of homemade explosives were found in the wreckage of the plane, it has emerged.

(Image: GETTY)

"One can unequivocally say that it was a terrorist act," Alexander Bortnikov, the head of Russia's FSB security service, told a meeting chaired by President Vladimir Putin recently.

Recently, ISIS released two videos claiming how they shot the plane down.

Since the disaster, many flights to and from Sharm have been suspended, raising concerns Egypt's tourism industry will be further ravaged.