Washington - The United States enacted more sanctions Tuesday on Iranian officials and companies suspected of aiding the country in the development of nuclear weapons.

The sanctions freeze the assets and cut off financial transactions with the six individuals and five companies listed by the State and Treasury departments.

Among those targeted was Mohsen Fakhrizadeh-Mahabadi, a top-level nuclear scientist in the Iranian foreign minister, as the US seeks to intensify pressure on Iran for its refusal to comply with UN Security Council demands to suspend uranium enrichment.

The other individuals are Yahya Rahim Safavi, accused of involvement in Iran's nuclear and ballistic missile programmes, Dawood Agha-Jani, who heads the main uranium enrichment facility at Natanz, Mohsen Jojati and two other officials.

The US and some European countries suspect Iran is seeking the know-how to build nuclear weapons. They have pushed three sanctions resolutions through three Security Council meetings to punish the Islamic state for continuing uranium enrichment, a process that could be used to build weapons.

Iran has defiantly expanded its uranium enrichment work and maintains it is solely for use in a nuclear reactor to produce electricity.

Sanctions were also slapped on five firms accused of playing a role in Iran's nuclear activities. They are: TAMAS; Shahid Sattari Industries; Seventh of Tir; Ammunition and Metallurgy Industries Group; and, Parchin Chemical Industries. (dpa)