U.N. Special Envoy for Syria Staffan de Mistura is calling for Turkey to intervene in the battle for Kobane, warning, “We know, we have seen it, what ISIL is capable of doing, when they take over a city.” (Reuters)

The U.N. representative for the Syria conflict appealed to the world Friday to “do something” to prevent what he said is the likely massacre of more than 10,000 people by Islamic State forces­ if the militants conquer the Syrian town of Kobane on the Turkish border.

“You remember Srebrenica? We do. . . . And probably we never forgave ourselves for that,” special envoy Staffan de Mistura said. The reference was to the July 1995 slaughter of thousands of civilians in the Bosnian city by Serbian paramilitary troops as a contingent of U.N. peacekeeping troops stood by.

“You remember Vukovar? You remember Rwanda?” he said, recalling other recent genocides where the international community chose not to intervene.

De Mistura called specifically on Turkey, which has closed its border adjacent to Kobane, to allow weapons and potential defenders, primarily Turkish Kurds, to cross into the Kurdish-populated town. Turkey has also resisted appeals to use its own troops to contest the militants.

While Turkey is a formidable military power, any use of its military in Syria would be fraught with complications. The Syrian Kurds have said they don’t want direct Turkish military intervention.

Islamic State militants fight on the streets of Syrian town of Kobane on the Turkish border in this amateur video obtained from a social media website. (Reuters)

At the same time, Arab members of the U.S.-led coalition against the Islamic State are opposed to any military intervention in Syria by Turkey, which they believe has underlying sympathy for the militants.

In meetings with U.S. envoys in Ankara on Thursday and Friday, Turkish officials agreed to participate in the coalition by giving unspecified support to efforts to train and equip the U.S-backed “moderate” opposition fighting both the militants and Syrian President Bashar al-Assad. Turkey is also considering a request to allow coalition aircraft to use its Incirlik Air Base. A Defense Department planning team will travel to the Turkish capital next week, administration officials said.

A State Department statement detailing the talks in Turkey, led for the administration by retired Gen. John Allen and diplomat Brett McGurk, did not mention Kobane. Both the United States and Turkey consider the Turkey-based Kurdistan Workers’ Party, or PKK, a terrorist organization.

Officials described a possible opening for dialogue with Syrian Kurdish leaders that might eventually allow some weapons and fighters to cross the border, although there is little optimism that Kobane can last that long.

The U.N. appeal came as pitched battles continued in the town, where local Kurdish fighters have been battling the Islamic State for three weeks. Militants who surround Kobane on three sides are said to control a quarter to a third of the town, although repeated U.S. airstrikes in the vicinity, including 16 Thursday and Friday, have helped the defenders hold their ground.

Anwar Muslim, the prime minister of the self-proclaimed canton, who spoke by phone from Kobane, said the intensification of strikes in recent days has “been very helpful and we thank the coalition.”

The fate of Kobane is a growing dilemma for the Obama administration, which has said that its airstrike strategy is designed to obliterate the Islamic State’s infrastructure and command system in Syria, rather than to intervene in local battles.

But near-constant media coverage of the town’s fight for survival — captured live by cameras positioned on nearby hills in Turkey, and by activist communications on social media — has transfixed international attention and increased pressure on Washington to do more.

Muslim, the Kurdish official in Kobane, said the fighters could hold on “for months” with sufficient air support. But in an emotional news conference in Geneva, de Mistura indicated that the end was imminent if help does not arrive quickly.

“We know it, we have seen it, what ISIL is capable of doing when they take over a city,” he said, recalling the slaughter of thousands in the Iraqi city of Mosul in the summer. ISIL is one of several acronyms for the Islamic State.

If Kobane falls, civilians in and around the town “will most likely be massacred,” de Mistura said.

With a pre­war population of about 45,000, Kobane is the self-proclaimed capital of a wider Kurdish district of what de Mistura said were about 400,000 people. Nearly half of those fled into Turkey in recent weeks, before the Turkish military sealed the border with tanks and troops.

The question of how many civilians remain in Kobane is the subject of some dispute. De Mistura said there are about 700 civilians still in the town itself, and about 12,000 noncombatants sitting at the border who have been blocked by Turkey from crossing.

State Department spokesman Marie Harf said Friday that while “the number remains low . . . it’s difficult to ascertain.” Besir Atalay, the deputy head of Turkey’s ruling Justice and Development Party, said that “there is no one left in Kobane except Kurdish . . . militants.”

“There is no tragedy in Kobane as cried out by the terrorist PKK,” Atalay said, according to a BBC report. “There is a war between two terrorist groups.”

The Kurdish political leader, Muslim, said that “thousands” of Kurds remain in Kobane.

Kobane’s takeover would also be a propaganda victory for the Islamic State in a war that the administration has emphasized is being heavily fought on the information front as well as with weapons.

“We would like to appeal to the Turkish authorities in order to allow the flow of volunteers at least and their own equipment in order to be able to enter the city and contribute to a self-defense operation,” de Mistura said.

He acknowledged that there are “political reasons, strategic reasons” why other countries find it difficult to intervene, but “when there is an imminent threat to civilians we cannot, we should not be silent.”

“Everyone who can should be doing what he can in order to control and hopefully stop this atrocious terrorist movement,” de Mistura said.

“There is humanitarian law. There is Srebrenica,” he said. “There are the images that we don’t want to see, we cannot see, and I hope you will not be seeing of people beheaded, of defenders and civilians.”

The United Nations, in its own 1999 report on the Srebrenica massacre, concluded that “the tragedy of Srebrenica will haunt our history forever.”

Liz Sly in Antakya, Turkey, and Brian Murphy contributed to this report.