http://www.haaretz.com/news/middle-east/iran-we-have-evidence-u-s-killed-nuclear-scientist-in-tehran-1.407286

Iranian state television said on Saturday that Iran had evidence the United States was behind the latest assassination of one of its nuclear scientists.
In the fifth attack of its kind in two years, a magnetic bomb was attached to the door of 32-year-old Mostafa Ahmadi-Roshan's car during the Wednesday morning rush-hour in Tehran. His driver was also killed.
The United States has denied involvement in the killing and condemned it.  Israel has declined to comment.

"We have reliable documents and evidence that this terrorist act was planned, guided and supported by the CIA," the Iranian foreign ministry said in a letter handed to the Swiss ambassador in Tehran, state TV reported.

"The documents clearly show that this terrorist act was carried out with the direct involvement of CIA-linked agents."

The Swiss Embassy has represented U.S. interests in Iran since Iran and the U.S. cut diplomatic ties shortly after the 1979 Islamic revolution.

State TV said a "letter of condemnation" had also been sent to the British government, saying the killing of Iranian nuclear scientists had "started exactly after the British official John Sawers declared the beginning of intelligence operations against Iran".