TEHRAN (Reuters) – Iran said yesterday it had evidence Washington was behind the latest killing of one of its nuclear scientists, state television reported, at a time when tensions over the country’s nuclear programme have escalated to their highest level ever.

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 the capital. His driver was also killed.

US Secretary of State Hilary Clinton denied responsibility and Israeli President Shimon Peres said Israel had no role in the attack, to the best of his knowledge.

“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 Swiss embassy represents US interests in a country where Washing-ton has no diplomatic ties. The spokesman for Iran’s Joint Armed Forces Staff, Massoud Jazayeri, said: “Our enemies, especially America, Britain and the Zionist regime (Israel), have to be held responsible for their actions.” Iran in the past has accused Israel of causing a series of spectacular and sometimes bloody mishaps to its nuclear programme. Israeli officials do not comment on any involvement in those events, although some have publicly expressed satisfaction at the setbacks.