The Kremlin on Tuesday confirmed for the first time that a bomb ripped apart the Russian jet that crashed in Egypt's Sinai Peninsula last month. The country has subsequently promised to hunt down the culprits. Russia had ignored assertions about the crash being a terrorist incident, allowing the official investigation to run its course till Tuesday. Alexander Bortnikov, head of Russia’s FSB security service, said that a homemade bomb containing up to 1 kilogramme of TNT had detonated during the flight, causing the plane to explode in mid-air, reported The Guardian. “We can unequivocally say it was a terrorist act,” Bortnikov said.

The country's President Vladimir Putin said the incident was “one of the bloodiest acts in modern Russian history” and increased airstrikes in Syria in response. He also ordered the country’s intelligence to track down those responsible. An Isis affiliate had claimed responsibility for the attack. “We will search for them everywhere wherever they are hiding. We will find them anywhere on the planet and punish them,” Putin said.

Russian news agency Interfax reported that the security service is offering a $50-million reward for any leads on those who planned the attack. Egypt, on Tuesday, issued a statement saying they had not made any arrests in the attack, refuting media reports that the authorities were holding 17 people.