Syrian Kurdish and rebel forces, backed by US-led air strikes, advanced on Thursday into Raqa province, where the jihadist Islamic State group has its de facto capital, a monitor said.

"The YPG (Kurdish People's Protection Units) and rebel forces captured 19 villages in Raqa province," said the Syrian Observatory for Human Rights.

"The US-led international coalition played a key role in the advance, bombing the IS positions and forcing its fighters to withdraw," said Observatory director Rami Abdel Rahman.

The advance comes as Kurdish and rebel forces push outwards from the border town of Kobane, from which they expelled IS forces after more than four months of fighting.

Since driving IS out of Kobane on January 26, Kurdish and allied forces have taken much of the surrounding countryside in northern Aleppo province and begun pushing east into neighbouring Raqa province.

They have captured some 242 villages around Kobane, including the 19 in Raqa province, according to the Observatory.

They are now 25 kilometres (15 miles) from Tal Abyad, another Kurdish-majority border town overrun by IS.

Located 65 kilometres east of Kobane, the town is used by IS fighters to cross into Turkey.

US may train Syrian rebels to guide air raids: Pentagon
Washington (AFP) Feb 18, 2015 - The United States will provide basic military training and equipment to Syrian rebels and may eventually instruct them on how to call in air strikes against Islamic State jihadists, the Pentagon said Wednesday.

But for the moment, the training will focus on fundamentals and not the more complicated task of directing US-led warplanes to a particular target, the skilled job of a forward air controller, Pentagon spokesman Rear Admiral John Kirby told reporters.

"The main purpose of the training is basic military structure and skills," Kirby said.

"I can't rule out that at some point, that we might find it useful for them to have the ability to help assist with targeting on the ground," he said.

"But I really want to walk you away from this notion that we're going to be producing Syrian forward air controllers. That is not the case."

About 1,000 US troops are due to deploy to Turkey, Saudi Arabia and Qatar to start training "moderate" Syrian opposition forces to take on the IS group in Syria. The instruction is due to start in mid-March and about 100 American trainers have already arrived in the region, according to Kirby.

The Pentagon plans to deliver pick-up trucks, light machine guns, ammunition and radios to the moderate rebels, officials told AFP.

In the recent battle for the northern Syrian town of Kobane, US aircraft were helped by Kurdish forces on the ground who relayed information about their own location and the position of IS fighters, Kirby said.

But he refuted some reports that suggested the Kurdish militia were acting as forward air controllers with the training and laser equipment to pinpoint the precise location of a target to a jet overhead.

"In Kobane, we didn't have, you know, trained forward air controllers on the ground there.

"What we did have eventually, and it took a little time, was some reliable sources inside Kobane, anti-ISIL forces, who had a good working knowledge of not just the town, but where ISIL was on any given day," said Kirby, using an alternative acronym for the IS group.

In the US-led fight against the IS militants, American commanders have placed a top priority on pushing back the extremists in Iraq first, while warning it could take years before a moderate Syrian rebel force is ready to make headway against the jihadists in Syria.