Islamist militants besieging the Syrian border city of Kobani appeared poised late Friday for a direct assault on the predominantly Kurdish enclave after a day of intense shelling.
After nightfall, at least three massive explosions, apparently from airstrikes, shook Kobani and the surrounding area, lighting up the evening sky. The blasts drew cheers from Kurdish refugees who fled the city and have been watching the fighting from hillsides on the Turkish side of the border.
U.S. warplanes have struck Islamic State positions repeatedly in the last week, and the sounds of a jet plane could be heard overhead late Friday. But there was no immediate confirmation from the Pentagon that the bombardment was part of the U.S.-led aerial assault on the militant group.
Islamic State fighters were less than a mile from Kobani, according to various accounts. The militants' intense shelling appeared to be an effort to soften the Kurdish defenses before a frontal invasion of the city, which is known as Kobani to its Kurdish residents but listed officially in Syria as Ayn al-Arab.
Kurdish fighters and representatives in Kobani contacted via cellphone insisted that the extremists had yet to enter the town.
"All rumors that Islamic State fighters are in the city are devoid of the truth," said Redur Xelil, representative of the Popular Protection Units, the Kurdish militia defending Kobani. "They are attacking us with heavy cannons, tanks, and mortars, but they have not entered the town. They are cowards."
Islamic State supporters flooded social media with videos depicting bearded Islamist fighters in cafes and restaurants near the entrance of the city.
Kurdish officials expressed confidence that their forces could mount a successful defense of Kobani, engaging in urban warfare on home terrain.
"If they come in, it will turn into a street fight," vowed Ismat Sheikh, political commander of the Kurdish militia in Kobani. "Once they are inside, we will make this town into a graveyard for them."
Kurdish representatives have called for more intense U.S. bombardment to thwart the advance of the well-armed militants, whose arsenal includes heavy artillery, tanks and armored vehicles, some of it U.S.-made and plundered from the Iraqi military.
Islamic State, an Al Qaeda breakaway faction formerly known as Islamic State of Iraq and Syria, or ISIS, has occupied vast swaths of Syria and neighboring Iraq.
"The strikes have yet to actually hit the heavy weaponry that Islamic State has on the front line," said Anwar Muslim, a Kurdish political leader in Kobani. "We can handle the fighters on our own, but we need to take out their heavy guns."
More than 150,000 Kobani-area residents, mostly Syrian Kurds, have fled to Turkey since the militant onslaught began last month.
Kobani appears to be a ghost town, according to videos. But Kurdish defenders are poised at strategic junctures, including hillsides and major entrances.
Ethnic Kurds boast a well-disciplined fighting force that has been one of the major bulwarks in Syria against Islamic State. Yet the Kurds are armed with little more than Kalashnikov rifles, rocket-propelled grenade launchers and Soviet-era Dushka machine guns mounted on pickups.
Islamic State has commandeered a vast arsenal during its sweep through Iraq. But in northern Syria, the group — occasionally allied with other Syrian rebel factions — has consistently been beaten back in attacks against enclaves defended by Kurdish militiamen, long their archenemy.
Here along the Turkish-Syrian border, the sound of shelling was heard throughout Friday, with occasional puffs of smoke and dust rising after the munitions struck. Slashes of tracer fire were visible across the sky.
Turkish troops were stationed at the border to prevent Kurdish volunteers from crossing to Kobani to assist in the town's defense, infuriating Kurds throughout the region.
Kurds are also angry that Turkey, with one of the region's strongest militaries, has refused to take action against the militants just across the border. Turkish officials have denied charges from Kurds and other critics that the government backs militants fighting in Syria.
On Thursday, lawmakers in Ankara, the Turkish capital, gave the military authorization to push into neighboring Syria and Iraq. But many observers said it was unlikely that Turkish forces would move in on Kobani, whose Kurdish militiamen are allied with Turkey's longtime nemesis, the Kurdistan Workers' Party, or PKK.
The crisis in Kobani appears to have elevated tension between Turkey and its Kurdish minority, which has long complained of discrimination and second-class treatment.
Islamic State said Friday that it was not targeting Kurds but only the "infidels" among the Kurdish population.
"Our battle with the Kurds is a war of creed and not one of nationalism," spokesman Abu Mohammad Adnani said in a statement.
"We do not fight the Kurds because they are Kurds, but we fight the infidels among them," he said, adding that there were many Kurdish fighters in the militant ranks.
Although most Kurds are Sunni Muslims, the sect of the Islamic State militants, Kurds generally embrace a less extreme form of Islam than does Islamic State. Kurdish militias in Syria are also steeped in the leftist, secular ideology of Abdullah Ocalan, the leader of the Turkish PKK, who is serving a life sentence in Turkey on a terrorism-related conviction.