MURSITPINAR, Turkey - Kurdish forces held out in Kobane on Thursday as a jihadist offensive entered its second month, but the Pentagon warned US-led air strikes may not prevent the Syrian border town's fall.
Pentagon spokesman John Kirby said the strikes had killed "several hundred" fighters with the Islamic State group and a Kurdish official inside Kobane said they had pushed the jihadists back from parts of the town.
But US officials warned that after significant advances in both Syria and neighbouring Iraq, the "tactical momentum" lay with IS.
While Iraqi troops prevented the jihadists from seizing a lynchpin provincial capital west of Baghdad, a senior US envoy admitted IS forces had scored important advances elsewhere.
John Allen, a retired four-star general and US envoy to the coalition fighting IS, said it would take time to build up local forces to defeat them.
In Kobane, Kurdish official Idris Nassen said IS had pulled back from some areas of the town but appealed for more air strikes as well as weapons to fight the jihadists.
"The international coalition has fought ISIS more effectively during the last few days," Nassen told AFP by telephone, using an alternative name for IS.
'Need more air strikes'
Nassen said Kurdish forces were "flushing out" IS fighters from the eastern and southeastern parts of the town, calling for more military assistance.
"We need more air strikes, as well as weaponry and ammunition to fight them on the ground," he said.
Kurdish forces have sustained heavy losses since IS launched its offensive on the Kurdish enclave around Kobane on September 16 but so too have the jihadists.
Ground fighting alone has killed more than 600 combatants, the Syrian Observatory for Human Rights said.
Between September 16 and midnight (2100 GMT) on Wednesday a total of 662 people were killed in ground fighting, said the Britain-based monitoring group, which has a wide network of sources inside Syria.
They included 20 civilians, Observatory director Rami Abdel Rahman told AFP.
IS lost 374 of its militants, while 268 people have been killed fighting on the Kurdish side, he said.
US Central Command said American aircraft carried out 18 raids near Kobane over two days, hitting 16 IS-occupied buildings.
But the Pentagon spokesman warned that jihadists are pouring into the region and the town "could very well still fall".
NATO member Turkey has stationed troops, tanks and artillery just over the border - in some cases only a few hundred metres (yards) from the fighting - but has not intervened.
It also has yet to allow US jets to mount attacks from its territory, and Turkish Prime Minister Ahmet Davutoglu said only Syrian refugees could cross into Syria to defend Kobane, rejecting Western calls to open the frontier.
President Barack Obama told military chiefs from more than 20 allies this week that they are facing a "long-term campaign" - dubbed Operation Inherent Resolve on Wednesday - against IS.
Obama has expressed special concern for Kobane, which has become a symbolic battleground in the fight against IS, and about halting the IS advance in Iraq's western Anbar province.
Government forces beat back an hours-long jihadist attack on the Anbar provincial capital Ramadi on Wednesday.
But Allen warned that the group has made "substantial gains" and maintained the "tactical momentum".'Antithesis of human rights'
IS has seized control of large parts of Syria and Iraq, declaring a "caliphate" in June and imposing its harsh interpretation of Islamic sharia law.
The group has committed widespread atrocities, including mass executions, torture and forcing women and children into slavery.
The new UN human rights chief, Zeid Ra'ad Al Hussein, told his first press briefing on Thursday that IS was the "antithesis of human rights".
"It kills, it tortures, it rapes," Hussein said.
"It is a diabolical, potentially genocidal movement, and the way it has spread its tentacles into other countries, employing social media and the Internet to brainwash and recruit people from across the globe, reveals it to be the product of a perverse and lethal marriage of a new form of nihilism with the digital age." Hussein renewed calls for Iraq to accept the International Criminal Court's jurisdiction with respect to alleged rights abuses by IS.
He also promised an updated UN assessment of the death toll in the more than three-year-old conflict in Syria, saying that it would certainly be well over 200,000.