The scientist (Mostafa Ahmadi Roshan) was killed in a brazen daylight assassination when two attackers on a motorcycle attached a magnetic bomb to his car. The killing was similar to earlier killings of scientists working on Iran's nuclear program.
The IRNA state news agency says Iran's Foreign Ministry has sent a diplomatic letter to the U.S. saying that the evidence shows the CIA provided "guidance, support and planning" to assassins "directly involved" in Wednesday's attack. The U.S. has denied any role in the assassination.
The news agency also reports that Iran has sent Britain a letter accusing it of having an "obvious role" in the killing, noting that a series of assassinations began after Britain's intelligence chief hinted at operations against Tehran.
The U.S. and its allies fear Iran's nuclear program aims to develop nuclear weapons. Iran denies the charges, and says its nuclear program is for peaceful purposes only.
