Despite the grisly intimidation campaign led by Sunni Arab extremists to sabotage the country's first democratic elections in five decades, US ambassador to Iraq John Negroponte was confident turnout would be strong.

The group of al-Qaeda's frontman in Iraq, Abu Musab al-Zarqawi, claimed Sunday on the Internet to have killed a leading member of Prime Minister Iyad Allawi's party.

"Your brothers in al-Qaeda's organisation in the Land of Two Rivers (Iraq) managed to assassinate Salem Jaafar al-Kanani, secretary of the traitor Allawi," said the statement, whose authenticity could not be confirmed.

The political director of Allawi's Iraqi National Accord party told AFP that Kanani, who was on the INA's parliament list, had been kidnapped on Wednesday.

In a separate audio message posted on the Internet, Zarqawi said next Sunday's election was a "wicked trap aimed at putting the Rafidha (a derogatory term for Shia Muslims) in the seat of power in Iraq."

It was the second inflammatory message from al-Qaeda's supremo in Iraq since Thursday as he sought to maximize violence among the country's fractious mix of Shias and Sunnis ahead of the vote.

Rebels rallied to Zarqawi's call over the weekend as car-bombs tore apart a Shia mosque and wedding party in the Baghdad region on Saturday, killing nearly 30 people.

But Allawi told the BBC: "We believe the elections themselves will help in putting an end to violence by fighting terrorists."

Meanwhile, eight Chinese hostages freed in Iraq have been handed back to Chinese authorities, a diplomat said Sunday, ending 24 hours of jitters and uncertainty about their whereabouts.

The release of the men, all migrant workers kidnapped Tuesday on their way home from a construction project, had been confirmed a day earlier but Chinese officials had been immediately unable to contact them.