Iran said on Saturday it had evidence that the United States was responsible for the assassination of the nuclear scientist earlier this week.

Iran said on Saturday it had evidence that the United States was responsible for the assassination of the nuclear scientist earlier this week.

Iranian state television said that the foreign ministry handed a letter to the Swiss ambassador in Tehran in which it accused Washington of the attack.

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

Last Wednesday, The nuclear scientist, Mostafa Ahmadi Roshan who is also a Chemical Engineering professor at a university in Tehran, was martyred after a magnetic bomb attached to his car exploded near Ketabi square in northern Tehran.

"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".