The Iranian Speaker of the Parliament, Ali Larijani, on Sunday reportedly called the assassination an of an Iranian nuclear scientist an "American-Zionist act of terror."
Darioush Rezaie, a university physicist, was shot outside his Tehran home Saturday by gunman on a motorcycle who fled the scene, the ISNA news agency said.
There was no immediate word from Iran on whether the slain man had been involved in its secretive nuclear program, which many world powers believe is geared to yield bombs.
Rezaie would be the fourth Iranian nuclear scientist to be targeted by assassins in recent months. Iran has previously blamed such killings on U.S. and Israeli agents