(Adds background, details, Treasury quote, byline)
By Timothy Gardner
WASHINGTON, Feb 6 (Reuters) - The United States said on Wednesday it has sanctioned state-sponsored broadcasters in Iran for helping the government censor its opposition, part of a broader U.S. effort to pressure Teheran over its nuclear program.
The Treasury Department named the Islamic Republic of Iran Broadcasting, its director, Ezzatollah Zarghami, and others as subject to sanctions that effectively block their access to the U.S. financial system.
U.S. law permits the Treasury Department to sanction anybody in Iran it believes restricts the flow of information to the Iranian public.
The Treasury Department also said that, as scheduled, U.S. sanctions that lock up Iran's oil earnings took effect on Wednesday. The sanctions prevent Iran from repatriating earnings it gets from its shrinking oil export trade.
Washington is trying to curtail Iran's oil revenues and access to them in an effort to slow its nuclear program, which the West believes is aiming to develop weapons. Iran says the program is solely for civilian purposes.
Officials have said the sanctions could largely shackle Iran's oil revenues within countries that are its customers. The funds would be useable only to purchase goods from those countries and prevent Iran from repatriating the earnings.
In addition to increasing economic pressure on Iran, the United States is cracking down on the government's restrictions on information. Human rights groups have said Iran is using state media reports to trample dissent, and have pointed to forced confessions of political detainees in front of state media outlets.
"We will also target those in Iran who are responsible for human right abuses, especially those who deny the Iranian people their basic freedoms of expression, assembly and speech," David Cohen, the undersecretary for terrorism and financial intelligence at Treasury, said in a release. (Reporting by Timothy Gardner; Editing by Doina Chiacu)