In the audiotape, a speaker identifying himself as Abu Musab al-Zarqawi — the leader of Iraq's al Qaeda affiliate — called candidates running in the elections "demi-idols" and said those who vote for them "are infidels."
"We have declared a fierce war on this evil principle of democracy and those who follow this wrong ideology," the speaker said. "Anyone who tries to help set up this system is part of it" — a clear warning to both candidates and those who choose to vote.
The speaker warned Iraqis to be careful of "the enemy's plan to implement so-called democracy in your country." He said the Americans have engineered the election to install Shiite Muslims in power.
On Jan. 30, voters will chose a 275-seat National Assembly and provincial councils in Iraq's 18 provinces.
The insurgency in Iraq is largely fought by extremists from the Sunni Arab minority, a community that lost influence and privilege with the fall of their patron Saddam Hussein.
In other developments:
Interim Prime Minister Ayad Allawi dismissed al-Zarqawi's remarks.
"We are insisting on smashing this aggressor group," Allawi told Al-Arabiya television. "The Iraqi people insist on victory and we will win."
The election has further split the rival religious communities, with Iraq's Shiite majority embracing the vote as a chance to cement their new power and many Sunnis calling for a boycott of the vote to protest U.S. military action in Sunni areas like Fallujah.
"Four million Shiites were brought from Iran to take part in the elections to achieve their aim of winning" most of the positions, the speaker in the tape said.
He railed against democracy for supplanting the rule of God with the rule of man and the majority, saying it was based on un-Islamic beliefs and behaviors such as freedom of religion, freedom of expression, separation of religion and state and forming political parties.
The tape surfaced as rumors spread in Iraq that al-Zarqawi had been captured. On Saturday, Iraqi Interior Minister Falah al-Naqib refused to comment on the rumors at a news conference. "Let's see. Maybe in the next few days we will make a comment about it," he said.
The United States has offered a $25 million reward for al-Zarqawi's capture or death — the same amount as for al Qaeda leader Osama bin Laden.
On Sunday, armed men blew up a designated polling station near Hillah south of Baghdad, Iraqi police Capt. Hatif Hadi said. No injuries were reported. Insurgents have targeted several schools and other buildings to be used as voting sites with gunfire and rockets in recent days.
Meanwhile, the Chinese Foreign Ministry confirmed Sunday that eight Chinese construction workers taken hostage by Iraqi insurgents have been safely transferred to Chinese custody.
In a statement posted on its Web site Sunday night, the Foreign Ministry said the eight men were in good health and the Embassy in Baghdad was arranging for their return to China.
The eight were seized this month by the Islamic Resistance Movement as they tried to leave Iraq for neighboring Jordan. In a videotape aired Saturday, the insurgents said they had decided to release the captives after China pledged to discourage its citizens from traveling to Iraq.
Elsewhere, Iraq's electoral commission said nearly 190,000 Iraqi expatriates had registered to vote from abroad. The highest number, about 41,000, signed up in Iran.
That's a fraction of the estimated 1.2 million Iraqis living abroad who are eligible to cast votes.
Niurka Pineiro, an official of the International Organization for Migration, which is handling the vote in 14 countries, said on Saturday that some people were scared that "when they go to these polling places some sort of mayhem may break out."
The agency extended the deadline for registration by two days — until Tuesday — to allow more Iraqi exiles to register.
Allawi said it was too early to talk about a withdrawal of U.S.-led forces.
"The terrorists and the evil forces are trying to break our will. They are trying to stop democracy from happening in Iraq," Allawi said in an interview Sunday on British Broadcasting Corp. television's "Breakfast With Frost" program.
Allawi said Iraqis ultimately want to see their own forces tackle the country's security problems.
"But it is too premature to talk about withdrawal (of multinational forces)," Allawi said.
"It is very early to talk about these issues," he said. "We wouldn't like to set a time at all. We would like to have the multinational forces helping us and training and developing both our army as well as our internal security forces."
Engineers have fixed water pipes that were sabotaged this month causing water shortages in Baghdad, the Iraqi government said Sunday.
"The (western Baghdad) Karkh water plant returned to full capacity after repairs to damaged water pipes in Tarmiyah district," 50 kilometers (30 miles) north of Baghdad. "The damage was caused by insurgent bombs" on Jan. 15, the government said.
Since the attack occurred, many Baghdad neighborhoods on both sides of the Tigris River had suffered a critical water shortage.