US-led air strikes have killed several hundred ISIL fighters around the Syrian town of Kobane, the US military has said, but cautioned that the town near Turkey's border could still fall to the Sunni rebel group.

The US-led coalition launched about 50 air strikes on the mainly Kurdish town of Kobane in the past 48 hours, the largest number since the strikes inside Syria began on September 22.

John Kirby, a Pentagon spokesman, said bad weather in Iraq had freed up coalition firepower to attack Kobane targets.

But he added the situation was fluid, with the Kurdish militia still controlling the town, although with pockets held by ISIL fighters.

"The more they want it, the more resources they apply to it, the more targets we have to hit," Kirby said, adding: "We know we've killed several hundred of them."

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The strikes, he added, had degraded ISIL's ability to move around forces and sustain themselves, "and it's not like they have a whole heck of a lot of ability to reconstitute that".

The siege of the mainly Kurdish town on the border with Turkey has become a focus of the US-led effort.

The UN has given warning of a massacre if the town falls to the rebels, who now control nearly half of it.

Kirby said only hundreds of civilians remained in the town. He also suggested improving weather in Iraq would bolster the intelligence picture needed for air strikes against ISIL there.

"As the weather improves, I think ... you'll see continued pressure applied as appropriate and as we're able to," he said.

Al Jazeera's Bernard Smith, reporting from the Turkey-Syria border, said on Thursday morning that coalition attacks had continued in intensity, adding that at least 11 took place overnight.

"It's quiet again in Kobane, with only the occasional burst of gunfire. And the Kurdish fighters say that the air strikes are making a difference," he reported.

Kirby's comments came during increased scrutiny in the US of its strategy to defeat the group in Iraq and Syria without sending ground troops into combat.

Obama on Tuesday told military leaders from more than 20 countries working with Washington to defeat the ISIL that he was deeply concerned about the extremist group's advances in Kobane and in western Iraq. 

Source: Reuters