A bomb attack in Tehran has killed an Iranian nuclear physics professor who backed an opposition candidate in last year's presidential election.
Iran blamed the United States and Israel for the remote-controlled bomb blast Tuesday. A U.S. State Department spokesman called the accusation "absurd."
Iranian state media report the bomb was on a motorbike that exploded outside the home of Dr. Massoud Ali Mohammadi, a nuclear scientist and professor at Tehran University. An Iranian foreign ministry spokesman says a preliminary investigation implicated Israel, the United States and what he called "their mercenaries in Iran."
Mohammadi publicly backed Iranian opposition leader Mir Hossein Mousavi in the disputed presidential election last year, and pro-reform Web sites had published Mohammadi's name on a list of university teachers who supported the reformer.
Iran's opposition accuses President Mahmoud Ahmadinejad of rigging the June vote to win re-election and has been staging anti-government protests for the past six months.
It is not clear if Mohammadi is connected to Iran's nuclear program, which the West suspects is aimed at developing a nuclear weapon. An Internet search finds Mohammadi focused his research on cosmology, which studies the dynamics of the universe and its large-scale structures.
Iran insists its nuclear work is for peaceful purposes only.
Meanwhile, Tehran prosecutors said Tuesday the court will hold its final hearing for the French academic on trial for spying. Clotilde Reiss was detained during the country's post-election protests and spent six weeks in an Iranian prison before authorities released her on bail in August.
France has rejected the spying allegation against Reiss.