Russia's FSB security service has offered a $50 million reward for information leading to the arrest of those responsible for downing a passenger plane over Egypt, the Associated Press reports.

FSB director Alexander Bortnikov announced Tuesday, November 17, that a homemade explosive device had blown apart the aircraft and that it was now clear that it was a "terrorist" act.

The FSB later appealed to "Russian and international communities for cooperation in identifying the terrorists" and offered "50 million U.S. dollars" reward.