On 28 June 1981 (7 Tir 1360 in the Iranian calendar; Persian: هفت تیر, Hafte Tir), a powerful bomb went off at the headquarters of the Islamic Republican Party (IRP) in Tehran, while a meeting of party leaders was in progress. Seventy-four leading officials of the Islamic Republic of Iran were killed, including Chief Justice Ayatollah Mohammad Beheshti the second-most powerful figure in the Iranian Revolution (after Ayatollah Ruhollah Khomeini). The Iranian government first blamed SAVAK and the Iraqi regime. Two days later, the People's Mujahedin of Iran was accused by Khomeini. Several non-Iranian sources also believe the bombing was conducted by the People's Mujahedin of Iran.