Mostafa Ahmadi Roshan

This undated photo released by Iranian Fars News Agency, claims to show Mostafa Ahmadi Roshan, who they say was killed in a bomb blast in Tehran, Iran, on Wednesday, Jan. 11, 2012, next to his son. Two assailants on a motorcycle attached a magnetic bomb to the car of an Iranian university professor working at a key nuclear facility, killing him and his driver Wednesday, reports said. The slayings suggest a widening covert effort to set back Iran’s atomic program. The blast killed Mostafa Ahmadi Roshan, a chemistry expert and a director of the Natanz uranium enrichment facility in central Iran, state TV reported. (AP Photo/Fars News Agency)