<center>US denies role in Iran nuclear scientist killing</center>

The United States rejected as "absurd" an allegation by Tehran that Washington had a hand in a bomb attack that killed an Iranian nuclear scientist, a State Department spokesman said on Tuesday as mystery surrounded the death of the opposition supporter.

"Charges of U.S. involvement are absurd," State Department spokesman Mark Toner said, after Iran's foreign ministry accused U.S. and Israeli "mercenaries" of being behind the bomb plot.

Massoud Ali Mohammadi, a particle physics professor at prestigious Tehran University, died when a bomb strapped to a parked motorcycle was triggered by remote control outside his home in northern Tehran, state media said.

Iranian nuclear scientist Massoud Ali Mohammadi

Tehran's foreign ministry spokesman Ramin Mehmanparast was quoted in Iranian media as seeing "signs of evilness by the triangle of the Zionist regime, America and their mercenaries in Iran in this terrorist incident."

He vowed that Iran would not be deterred from its nuclear efforts, however.

"Such terrorist acts and the physical elimination of the country's nuclear scientists will certainly not stop the scientific and technological process but will speed it up," he said.

Iran's chief prosecutor also implicated U.S. and Israeli intelligence services in the bombing that killed nuclear scientist Massoud Ali Mohammadi.

Bomb attacks are rare in Iran although several security officials and members of the elite Revolutionary Guards have been killed in bombings by rebels in restive Sistan-Baluchestan province in eastern Iran. [adm/alarabiyya]