Iranian security forces are responsible for the death of the daughter of a veteran opposition figure at her father\'s funeral, the United States has said in condemning the regime\'s repression. \"Eyewitness and reliable accounts of Haleh Sahabi\'s death yesterday at her father\'s funeral in Iran are making it clear that Ms Sahabi died as a result of reprehensible actions taken by Iranian security forces,\" said Mark Toner, a State Department spokesman. He condemned the activist\'s killing \"in the strongest possible terms,\" deplored Tehran\'s \"unsatisfactory\" explanations and noted that the government shut down a memorial for Sahabi. The Iranian opposition website Kaleme.com reported that the 54-year-old political and social activist died from cardiac arrest Wednesday when she was confronted by security forces during the funeral of her father, Ezatollah Sahabi. Kaleme.com, the website of opposition leader Mir Hossein Mousavi, quoting Sahabi\'s son Yahya Shamekhi said she was protesting at the security forces halting the funeral procession and taking her father\'s body. According to her uncle quoted by Kaleme, the woman died due to \"the beatings given to her, (which) were severe.\" But her son Shamekhi, quoted by Kaleme.com and other media, said that his mother died \"not due to beatings but because of a cardiac arrest.\" \"It is unfathomable that a government would be so terrified of its citizens that it would order the use of force against a daughter mourning at her father\'s funeral,\" Toner said in a statement. \"Indeed, this is a government that regularly brutalizes its citizens, imprisoning them under questionable charges, torturing them, cutting them off from the rest of the world and denying their fundamental human rights.\" He said the United States would ask that the special rapporteur on Iran at the Human Rights Council \"fully investigate\" the incident.