Iran is looking at \"punishing\" those behind the assassination of one of its nuclear scientists, a senior military official said on Saturday, pointing the finger at the United States, Israel and Britain. \"We consider committing a terrorist act of killing a scientist to be a threat to the nation... We are looking at punishing those who were behind the scenes of the martyrdom (assassination) of Mostafa Ahmadi Roshan,\" the deputy chief of Iran\'s joint armed forces, Masoud Jazayeri, was quoted as saying by several media. Iran\'s response will be \"tormenting\" for those responsible, he said, adding: \"The enemies of the Iranian nation, such as the United States, Britain and the Zionist regime, should be made accountable for their actions.\" Ahmadi Roshan, a 32-year-old deputy director of Iran\'s main uranium enrichment plant, was killed along with his driver on Wednesday when assassins on a motorbike fixed a magnetic bomb to his car. He was the third nuclear scientist to have been murdered in similar circumstances in Tehran over the past two years. Iran\'s supreme leader, Ayatollah Ali Khamenei, said on Thursday that the \"abominable\" killing was committed \"with the planning or support of the intelligence services of the CIA and Mossad\" of the United States and Israel. Khamenei said in a statement that Tehran would \"continue with determination\" its nuclear activities, which Western governments suspect mask a drive for a weapons capability despite repeated denials. Some media close to Iran\'s conservatives have called for \"retaliation\" against Israeli officials. Washington has strongly denied any involvement with the assassination. Israel, widely seen as the prime suspect, has neither denied nor confirmed involvement, in line with its policy of not commenting on intelligence matters. Tehran has formally demanded that the UN Security Council condemn the \"terrorist\" killing. Its foreign ministry has also sent letters to the US and British governments accusing them of involvement in the scientists\' assassinations, newspapers reported on Saturday.