WASHINGTON (Reuters) - U.S. special forces advisors are within miles of rebels who they are helping to capture the strategic Syrian town of al-Shadadi from Islamic State but are away from the front lines, a U.S. military spokesman said on Friday.

Syria Democratic Forces fighters look through a scope and a pair of binoculars on the outskirts of al-Shadadi town, in 47 village, Hasaka countryside, Syria February 19, 2016. REUTERS/Rodi Said

The United States sent dozens of special operations troops to northern Syria last year to advise opposition forces in their fight against the militant group.

Those forces have been helping Syrian rebels fighting Islamic State through planning, re-supply and helping call in and coordinate air strikes, said Colonel Christopher Garver, a spokesman for the U.S.-led military coalition against Islamic State.

U.S. advisors and coalition air strikes assisted approximately 6,000 rebels, known as the Syrian Democratic Forces (SDF), in encircling the city from approximately Feb. 15 to Feb. 22, Garver said.

“The SDF overwhelmed ISIL forces around Shadadi and isolated the city in just six days,” Garver said, using an acronym for Islamic State. “When our planners or coordinators are connected with them, in terms of making sure their air strikes are in the right place, clearing fires so that we can quickly attack targets that appear to the front of the SDF forces, that goes much smoother.”

The U.S. forces were not on the ground with the Syrian rebels, and were also not so close that they could see the front lines, Garver said, but were within miles of the battle.

“They operate at the next higher headquarters,” he said. “They are not down on the ground with the fighters or in the lower echelon headquarters.”

The United States views the capture of al-Shadadi, a logistics hub, as a strategic gain and step toward defeating Islamic State, also known by its Arabic acronym Daesh.

“The loss of Shadadi increases the time, difficulty, and risk to Daesh as it attempts to move between Syria and Iraq,” Garver said.

The rebels have cleared about 75 percent of the town of Islamic State, he said. The U.S.-led coalition conducted about 80 air strikes on Islamic State targets during the course of the battle, Garver said.

About 20 rebel troops and 260 Islamic State fighters were killed during the battle for the city, he said. He did not have an estimate for how many Islamic State fighters or civilians were in the city when rebels attacked.