The Kremlin announced Tuesday that traces of explosives have been found in the debris in the Metrojet passenger jet that crashed when it took off from Egypt last month, according to NBC News.
Egyptian authorities also told NBC News two employees at the Sharm el-Sheikh airport were detained and being questioned in connection to the bombing.
Alexander Bortnikov, the chief of the country's FSB domestic security agency, said that a bomb equivalent to 2.2 pounds of TNT exploded on board the aircraft, according to the Kremlin.
A $50 million reward has been offered by Russia's domestic security agency for information on who brought down the jet, NBC News reported.
The plane crash killed all 224 people on board, most of them Russian tourists.
