WASHINGTON: The United States is seeing signs that new efforts to draw Sunni tribesmen into Iraq’s battle against ISIS may be taking root at a military base near the fallen capital of Sunni-dominated Anbar province, U.S. officials say.

A U.S. defense official told Reuters the first group of 500 Sunni recruits would soon complete training at the Taqaddum military base near the city of Ramadi, making way for a second group of about 500 Sunnis who have agreed to participate.

The number of confirmed Sunni recruits for Taqaddum is double the amount first disclosed last month by the U.S. military and follows U.S. President Barack Obama’s June 10 order to deploy American troops for the first time to the base.

About 400 American troops are now working at Taqaddum, some engaging with Sunni tribal leaders but not directly training the forces, the officials said, speaking on condition of anonymity.

Iraq’s army has been burdened by a legacy of sectarianism in Anbar, whose dominant Sunni population resented former Prime Minister Nouri al-Maliki’s Shiite majority government and were incensed when he ordered troops to clear a protest camp in Ramadi in December 2013.

One of the goals of the U.S. deployment to Taqaddum is encouraging Sunni tribes to join the battle against ISIS, drawing in fighters who felt unsafe traveling to the other U.S. outpost in Sunni-dominated Anbar province, at the Ain al-Asad air base.

Taqaddum is located only 25 km from Ramadi, Anbar’s capital, which fell to ISIS in May. Iraq is readying a counteroffensive to retake it.

The Sunni recruits at Taqaddum would represent a significant chunk of Sunni recruits so far for the still overwhelmingly Shiite popular mobilization forces.

The first U.S. official estimated about 6,000 Sunni recruits.

A second official said Sunnis had so far demonstrated commitment to the training – noting that all 500 had returned to the base after a brief break to celebrate the holy month of Ramadan with their families.

Iraq’s government also appeared invested, quickly providing small arms and ammunition for the Sunnis and directing funds to improve base facilities for them.

“There’s a large [Sunni] population out there that’s ... going to wait and see if this takes or not. And these are indications to me that this has taken,” the second official said.