BAGHDAD, Iraq – Iraq’s interim prime minister warned yesterday that insurgents are trying to foment sectarian civil war as well as derail elections, while thousands of mourners turned out for funerals in the Shiite holy cities of Najaf and Karbala a day after car bombs killed 67 people.

Prime Minister Allawi said the mainly Sunni Muslim insurgents, who are presumed to be behind Sunday’s bloody attacks, want to “create ethnic and religious tensions, problems and conflicts…to destroy the unity of this country.”

“These attacks are designed to stop the political process from taking place in Iraq,” Mr. Allawi told reporters. He added that his administration would not be deterred despite expecting more strikes before key January 30 parliamentary elections – the first free vote in Iraq since the overthrow of the monarchy in 1958. In a new attack in Karbala yesterday, a bomb exploded at a police checkpoint, but inflicted no casualties. Police said they arrested the attacker.

Shiite Muslims, who make up around 60% of Iraq’s people, have been strong supporters of the electoral process, which they expect to reverse the longtime domination of Iraq’s Sunni minority. The insurgency is believed to draw most of its support from Sunnis, who provided much of Saddam Hussein’s former Baath Party leadership.

Shiite officials and clerics blamed Sunnis for Sunday’s bombings, which caused the worst carnage in Iraq since July. The strikes appeared designed to cause heavy casualties, and provoke reprisals by Shiites against Sunnis.

The bombings – aimed at a funeral procession in Najaf and a packed bus station in Karbala – again highlighted the capability of the guerrillas to strike.

Their attacks have undermined confidence in repeated claims by American military commanders that the capture of the insurgent stronghold of Fallujah last month dealt a serious blow to the insurgency.

The head of Iraq’s electoral commission appealed to security forces to protect his officials after three were shot to death in a daylight attack Sunday by dozens of guerrillas in the heart of Baghdad. The ambush was the latest attack on Iraqi officials working to organize the vote.

“We send an appeal to the Iraqi government and all the people to protect our employees,” Abdul Hussein Al-Hindawi said. “We have no real protection because we work everywhere in the country and have more than 6,000 employees.”

In New York, U.N. Secretary-General Annan strongly condemned Sunday’s violence and called on Iraqis “to come together in a spirit of national reconciliation,” U.N. spokesman Fred Eckhard said.

“No cause can justify the killings of innocent civilians and the cold-blooded murder of election workers,” Mr. Eckhard said.

Mr. Allawi said yesterday that a big factor in the strength of the insurgency was the dismantling of Iraq’s security forces after the American-led invasion that ousted Saddam’s regime.

“What is happening is that we are facing an enemy heavily supported even in some cases with superior weapons,” he said. “We will have setbacks, we are having setbacks, but we are determined to continue the fight.”

After the slaying of the election workers Sunday, police and troops were nowhere to be seen while gunmen conducted spot checks of cars and their occupants on Haifa Street, the capital’s main thoroughfare. It was only after the insurgents had fled after the slayings of the election workers that American Apache helicopters appeared over the scene.

There have been fears the intimidation campaign aimed at electoral workers will not only hurt preparations for the ballot, but also could reduce voter turnout enough to bring the legitimacy of the election into question.

As mourners went to funerals in Najaf yesterday, police imposed a ban on cars entering the downtown area that houses the Imam Ali shrine to prevent future bombings, Governor Adnan al-Zurufi said. Najaf police chief Ghalib al-Jazaari said 50 people had been arrested in connection with the bombings. Some of them confessed to having links with the intelligence services of neighboring Syria and Iran, he claimed.

The Iraqi defense minister, Hazem Shaalan, has accused both Iran and Syria of supporting terrorism in Iraq, although Mr. Allawi dismissed the allegations yesterday, saying they did not reflect the government’s position.