KHAN BENI SAAD, Iraq (AFP) -- Sunni Arab militiamen, who are widely credited with turning the tide of the war against Al-Qaeda in Iraq, now fear for their future as US troops withdraw from country's towns and cities.

The former rebels and tribesmen, known as Sahwa or Awakening councils, fret that they are not only in the firing line for Al-Qaeda but also viewed with suspicion by the Shiite-led central government.

"When American soldiers were around, we were confident. We knew the terrorists would not come and attack us. They knew who was the strongest. But after their departure..." sighed Abu Ali, a 25 year-old militiaman who asked not to give his real name.

He and a friend are keeping watch over a desert road near Khan Beni Saad in the south of Diyala province, formerly one of the most violent districts in Iraq where Al-Qaeda held sway.

The two Sahwa guards shelter from the wind in a hut feebly lit by one bulb. The younger one, baby-faced Abdullah, 19, speaks in agreement while fiddling with the strap of his old Kalashnikov.

"When the Americans leave, the Iranian militias will arrive," he said, alluding to Shiite radical leader Moqtada al-Sadr's Mahdi Army militia and the Badr Organisation run by the formerly Tehran-based rebel group, the Supreme Iraqi Islamic Council.

The 1.5 million people in Diyala are mostly Sunni Arabs but there are also large Shiite Arab and Kurdish communities.

The Sahwa militia boasts 15,000 men, although an Iraqi security source said their true strength was closer to 10,000.

A few kilometres (a couple of miles) away on an unmade road, three other Sahwas are also standing guard. They are peasants from the nearby village of Abu Bassal.

"Very definitely we are scared," 19 year-old Alaa Taleb says when asked about the departure of American troops, who will, however, occupy five bases outside urban areas until 2011, one of them near Khan Beni Saad.

In the darkness of the night, the barking of a dog puts them on the alert. "If terrorists come, they will kill us. How do you think we can defend ourselves with that?" complains Qassam Ali, 25, showing his ancient gun.

A dispute over pay also threatens the Sahwas' loyalty. Many fought with insurgents before changing sides in 2007 and collecting wages of 300 dollars a month from the US military.

Since January, the money has come from the government, which slashed the monthly stipend to 100 dollars and often pays it late.

"We have been waiting for our wages since January," Abdullah al-Obeidi, a local Sahwa chief, said during a visit to the US base dubbed Key West.

Sitting under a large American flag, he shakes the hand of an American officer and says: "You can't go. You have only done half the job."

Bitterness is clear in his voice. "Without us, they would not have beaten Al-Qaeda. We helped them a lot and security would deteriorate rapidly if we stopped what we are doing," he said.

The commander said he has been arrested by the Iraqi army several times without any reason being given. "After the Americans withdraw from towns, we will be targeted by the government and by Al-Qaeda," he predicted.

US Captain Jeffrey Harmon admitted: "They are nervous because they are Sunnis and for a long time the enemies were Shia."

But he added: "Sahwa are supposed to be temporary. They were transferred to the government and they will be integrated in the security forces or hired for local jobs."

By Mehdi Lebouachera