The demonstration, along with a similar one in the powerful cleric's Sadr City stronghold in north Baghdad, saw protesters walk from the main mosque in Kufa, 145 kilometres (90 miles) south of Baghdad, to the centre of the town.

Demonstrators shouted, "No, No, America!", "No, No, Israel!", "Yes, Yes, Islam!" and "Yes, Yes, for the Koran!" and held up a banner that read, "We demand action against those who insult the Koran anywhere."

"Muslims should stand firmly against those who insult the things that are sacred to Islam, and at the very top of that list is the Koran and the Prophet Mohammed," said Ahmed al-Kaabi, one of the demonstrators.

The rally came after US pastor Terry Jones carried out a burning of copies of Islam's holy book and a depiction of Mohammed in front of 20 people at his church in Gainesville, Florida, on April 29, with the burning streamed live over the Internet.

A video of the burning was uploaded to YouTube by the pastor's supporting group "Stand Up America Now."

The actions were taken to protest the imprisonment in Iran of a Christian clergyman, Youcef Nadarkhani.

"My life in Baghdad (is) in high risk," the key Sunni Arab leader told journalists in Istanbul, where he has been based more than a month.

Iraqi Prime Minister Nuri al-Maliki's decision to dissolve the vice president's guard unit had increased the threat level, said Hashemi, who is being tried in absentia in a Baghdad court.

"I have great...mistrust about the standard of justice," he explained.

He has challenged the legitimacy of the trial in the Central Criminal Court of Iraq (CCCI), claiming the federal court should have handled the case because he is a sitting vice president.

"This in itself is a straightforward violation of the constitution," he said.

Hashemi and several bodyguards are charged with killing six judges and senior officials, including a lawyer and the director general of the security ministry.

Authorities issued an arrest warrant for Hashemi in December after the US completed its pullout and he first sought refuge with Iraqi Kurds.

The autonomous population refused to hand him over to Baghdad and he then fled to Turkey, after stops in Qatar and Saudi Arabia.

Rejecting claims that he was a "fugitive", Hashemi said he would soon be back in Arbil, the capital of Kurdistan in northern Iraq.

"My colleagues in Iraq suggested I should postpone (the) trip (back to Arbil) for a few days, to provide more convenience to the intensive dialogue going on presently in Baghdad," he said, an apparent hint that a political deal could be reached to ease his return.

Should the trial in absentia continue, Hashemi said he would likely be sentenced to death and that he would then call on the international community "to render help as quick as possible."

Hashemi's trial began Thursday, but was delayed until May 10. His lawyers want the case to be heard by a special court and not by the CCCI.

Hashemi supporters have said they fear the trial will otherwise be politicised.

The decision to charge Hashemi sparked a political crisis that saw the vice president's bloc boycott cabinet and parliament over accusations al-Maliki, a Shiite, was monopolising power.