Russia's security chief said Tuesday the passenger plane that crashed over Egypt last month was downed by a homemade bomb taken aboard the aircraft.
Calling it an act of terrorism, FSB Director Alexander Bortnikov announced that an investigation had found traces of explosive material in the wreckage and luggage aboard the Airbus A321 aircraft, Interfax reported. He said the improvised explosive device set off aboard the plane was equivalent of up to 1.5 kilograms of TNT.
Russian President Vladimir Putin said it was among the bloodiest of crimes and vowed to find and punish those responsible, according to Interfax. He said he has asked his intelligence community to focus on finding the culprits and said action would be taken against them.
Putin also vowed to increase airstrikes against the Islamic State over Syria. An affiliate of the terror group previously took credit for downing the jet.
The plane crashed over the Sinai Peninsula on Oct. 31, killing all 224 aboard.
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