The US and European Union denounced Iran at the top UN human rights body for its bloody crackdowns on peaceful protests and other violations since disputed presidential elections a year ago.

The accusations were made at the UN Human Rights Council before Washington hopes to win a fourth round of UN Security Council sanctions against Iran over its nuclear programme. That vote could come on Wednesday.

US ambassador Eileen Chamberlain Donahoe told the Geneva forum the rights situation in Iran was "one of grave concern".

"Since last June's contested election, the Iranian government has engaged in systematic infringement of the Iranian people's rights to basic liberty, freedom of speech and political association," she said.

Some 250 people who were arrested, prosecuted and convicted for participating in post-election protests have had their sentences upheld by an appellate court, Donahoe said. Fifty among them were still serving terms, she said.

"At least 35 journalists are currently imprisoned in Iran because of their efforts to report on civil and political activity since the election," she added.

Conservative and reformist newspapers in Iran had been shut down and Iranian authorities systematically block the Internet sites of human rights groups, independent media and civil society organisations, the US envoy said.

Iranian authorities also routinely harass human rights defenders, she said.

The UN General Assembly condemned Iran last December for a violent crackdown on protesters after the election, which Iran's opposition says was rigged in favour of Iranian President Mahmoud Ahmadinejad.

There was no immediate response to the US speech from the Iranian delegation, whose prepared remarks focused on what it called worrying trends of racism in many EU states and abuses committed by the US in its declared "war on terror".

Mohammad Javad Larijani, secretary-general of the Iranian High Council for Human Rights, is due to address the 47-member forum on Thursday.

Larijani was quoted last month by the IRNA news agency as saying that Iran had invited UN High Commissioner for Human Rights Navi Pillay to visit the Islamic Republic. Pillay has repeatedly voiced concern about a crackdown on dissent in Iran.

Spain's ambassador Javier Garrigues, speaking on behalf of the European Union, called attention to what he called the violent and alarming suppression of peaceful protesters in Iran following the presidential election.

The EU deeply deplored Iran's consistent failure to conduct an impartial, transparent and thorough investigation into the allegations of serious human rights violations, he said. – Reuters