The Bush administration moved Tuesday to impose financial sanctions on Iranian officials and companies accused of helping the country develop nuclear weapons. The action by the departments of State and Treasury marks the latest effort to tighten the financial noose on Iran, which the United States accuses of bankrolling terrorism and seeking a nuclear bomb. Mohsen Fakhrizadeh-Mahabadi, a senior scientist at the Ministry of Defense and Armed Forces Logistics, was among those targeted on Tuesday. The others cited were: Yahya Rahim Safavi, a commander of the Iranian Revolutionary Guard Corps.; Dawood Agha-Jani, who is involved in Iran's nuclear program; Mohsen Hojati, involved in the country's ballistic missile program; Mehrdada Akhlaghi Ketabachi, the head of the Shahid Bakeri Industrial Group; and Naser Maleki, head of the Shahid Hemmat Industrial Group and an official in the Iranian defense ministry. The action means that any bank accounts or financial assets found in the United States that belong to these people are frozen. Americans also are prohibited from doing business with them. The departments also covers the TAMAS Co. for its alleged involvement in enrichment-related activities and Shahid Sattari Industries. The US government also imposed sanctions on three other entities believed to be owned or controlled by Iran's Defense Industries Organization, which was put on the United States' blacklist last year.