Haditha, Iraq ? U.S. Marines handed out thousands of fliers and copies of Iraq’s new constitution Thursday, urging people to vote in this Sunni Arab town that only a week ago was the target of U.S. airstrikes.

But with the crucial referendum on the charter just two days away, many residents still did not know where to cast ballots. Across Iraq’s insurgent heartland – the overwhelmingly Sunni Arab province of Anbar – fears of attacks have limited plans to only a handful of heavily fortified polling stations.

Even then, the sites were still unannounced Thursday for security reasons, officials said, and a ban on vehicle traffic will force many residents to walk miles to vote.

And American forces were not the only ones waging a public campaign: Insurgents had distributed fliers of their own before the U.S.-led offensive, Iraqi soldiers said, threatening that anyone who votes will be beheaded.

All these factors could depress turnout in a region key to whether the constitution is accepted or rejected.

The U.S. military hopes Sunni participation will draw those who feel marginalized into the political process and erode support for the insurgency.

Sunni factor

An Iraqi policeman assigned to a hospital protection unit casts his vote in Iraq's referendum on the new constitution in Baghdad, Iraq. Hospitals and prisons organized voting two days ahead of the official date with thousands of Iraqi detainees who have not been brought to trial allowed to vote early in the constitutional referendum at U.S. prisons such as the notorious Abu Ghraib detention center .

It may not work that way in Anbar, a province of 1.3 million people. Almost the entire population is Sunni Arab, the minority that held power under Saddam Hussein. Many Sunnis believe the constitution will only solidify the domination of majority Shiites and the Kurds – a sentiment that could drive some to join those fighting the government and its U.S. backers.

And whether the final result on the constitution is “yes” or “no,” Sunnis here may feel more alienated than ever if they didn’t feel they were able to vote.

Skepticism

One Haditha resident, an engineer with four children who previously served in the Iraqi air force, stood aside as Marines searched his home for illegal weapons. He did not even know when the referendum was being held, but added that he wouldn’t vote anyway because he suspected the vote was rigged.

“There are many forces in Iraq and Haditha that prevent my voice from being heard,” he said. “This constitution was not made under fair conditions, you know.”

“There is no government in Haditha. Only the government of the fighters,” he added, asking that his name not be used because of fear of insurgent reprisal.

Other Marines heard similar reluctance from residents as they handed out fliers about the referendum, though some people said they would consider voting in the coming days.

On Oct. 4, Marines swept into the Euphrates River town of Haditha and two neighboring towns – Parwana and Haqlaniyah – in an offensive dubbed River Gate to force out insurgents and install a long-term Iraqi security presence. The operation started with a major air barrage and five Americans killed by roadside bombs and fighting. Then, troops moved into the towns to find little insurgent resistance, with most fighters hiding or having fled.

Now Marines hope to cap off River Gate by drawing thousands to the polls on Saturday.

Outside the Haditha hospital, still charred from a spring suicide car bombing, four men agreed they would decide how to vote after looking through a copy of the constitution handed out by the Marines. A fifth man said it was his “democratic right” to abstain.

Across the street was a spray-painted threat scrawled in English, addressed to the Marines: “It’s better for you to leave. Otherwise you will be killed by Muslim fighters.”

Current plans, not released to the public yet, call for only a small number of stations in Haditha, Haqlaniyah, and Parwana.

The situation is similar in much of the western half of Anbar province, a vast desert region stretching to the Syrian border, where U.S. and Iraqi forces are few and only a handful of polling stations will be scattered among the towns along the Euphrates.

Polls are more plentiful in the cities of the eastern part of Anbar, closer to Baghdad, where U.S. and Iraqi troops are more concentrated. There are 31 stations in Fallujah, Anbar’s largest city of several hundred thousand people.

“I just hope they go out and vote,” said Cpl. Joseph Dudley of Los Gatos, Calif., of the 3rd Battalion, 1st Regiment, after nailing a flier to the side of home in Haditha. “I talked to a few people and I don’t know if they felt secure.”