BAGHDAD -- Gunmen wearing Iraqi army uniforms burst into the home of a Sunni Arab sheik yesterday, killing him, three of his sons, and a son-in-law in an attack police said may have been aimed at discouraging members of the minority from participating in next month's election.
Khadim Sarhid al-Hemaiyem, who lived on the outskirts of Baghdad, was the leader of a branch of the Dulaimi tribe, one of the biggest in Iraq. His brother is a candidate in the Dec. 15 parliamentary election; three of his sons had been policemen and another son was slain last month north of the capital, police and family members said.
Elsewhere, an American soldier from Task Force Baghdad died of a gunshot wound yesterday in the center of the capital, the US military said. At least 2,098 US service members have died since the Iraq war started in March 2003, according to an Associated Press count. The AP erroneously reported yesterday that the toll had reached 2,100.
The attack on the sheik and his family took place amid a major campaign by US and Iraqi authorities to encourage Sunni Arabs to vote next month in hopes of luring them away from the insurgency.
Some insurgent groups have declared a boycott of the election and have threatened politicians who participate. Police said they suspected the sheik's death was designed as a warning to Sunni Arabs against heeding the US call.
However, the Association of Muslim Scholars, a hard-line Sunni organization believed to have links to insurgents, condemned the slayings and linked them to what many fear is a campaign against Sunnis by the Shi'ite-led government security services.
''We warn the government against continuing with this tyranny," association spokesman Abdul Salam al-Kubaisi said.
The Iraqi Islamic Party, the country's biggest Sunni political group, also condemned the assassination and demanded that the Defense Ministry ''control its forces and punish the perpetrators."
Police Major Falah al-Mohammedawi denied that government forces were involved in the killings and blamed the insurgents.
''Surely, they are outlaw insurgents. As for the military uniform, they can be bought from many shops in Baghdad," he said, adding that several police and army vehicles had been stolen and could be used in raids.
The United States hopes that a big Sunni turnout next month will produce a broad-based government that can win the minority's trust, helping to take the steam out of the Sunni-led insurgency and hasten the day when American and other foreign troops can return home.
Many Sunnis, who constitute about 20 percent of Iraq's 27 million people but were dominant under Saddam Hussein, boycotted the January vote, enabling rival Shi'ites and Kurds to dominate the transitional government, a development that heightened tensions.
At the same time, US military commanders have warned that insurgents will probably escalate attacks in hopes of undermining the election.
In other election-related violence, gunmen blocked the road leading to the Communist Party's branch office in Baghdad's Shi'ite district of Sadr City, broke into the party building late Tuesday, and killed two activists.
''The government should bear the responsibility of providing the necessary protection in order to ensure a safe atmosphere for the elections," the party said yesterday in a statement.
Despite the violence, Senator Joseph I. Lieberman, Democrat of Connecticut, said he was encouraged by the political progress so far in Iraq.
Lieberman, who arrived yesterday in Baghdad to spend Thanksgiving with US troops, told Prime Minister Ibrahim al-Jaafari that US forces will remain in Iraq until their mission is complete, despite growing unease in Congress about the conflict. ''We cannot let extremists and terrorists, a small number, here in Iraq deprive the 27 million Iraqis of what they want, which is a better, freer life, safer life for themselves and their children," Lieberman said.
Lieberman, a member of the Senate Armed Services Committee, said the cost of success in Iraq would be high ''but the cost for America of failure in Iraq would be catastrophic -- for America, for the Iraqi people, and I believe for the world."