SAn explosion rocks Syrian city of Kobane during a reported suicide car bomb attack by the militants of Islamic State group on a People's Protection Unit (YPG) position in the city center of Kobane, as seen from the outskirts of Suruc, on the Turkey-Syria border. (Gokhan Sahin/Getty Images)

The men who snatched Abu Issa from the streets of this southeastern city were Turkish gangsters, but their client was the Islamic State, and they had been promised good money to spirit the Syrian rebel commander across the Turkish border into Syria.

The effort ultimately failed, but the story of the brazen daylight kidnapping and its chaotic conclusion has raised troubling questions about the militant group’s growing reach into Turkey, as well as the capacity of the Turkish authorities to contain it.

Over the past year, this NATO ally has come under intense pressure from the Obama administration to do more to halt the flow of thousands of foreign fighters who have swarmed into the country to join the war in Syria. Turkey says it is trying, and strict new border procedures, along with reinforced patrols, barbed wire and watchtowers, are evident at all the major crossing points into Syria.

Yet as the abduction attempt in recent days illustrated, the Islamic State has already established deep roots within Turkey and among the more than 1 million Syrians who have taken refuge there. One indication of that was this month’s discovery in the southeastern city of Gaziantep of a vast quantity of explosives and more than 20 suicide vests that police said were thought to have been stockpiled by the Islamic State.

Moderate Syrian rebels and activists living in Turkey say they often recognize men whom they suspect of belonging to the extremist group on the streets or in cafes frequented by Syrians. One commander recently suggested relocating an interview with a reporter from a Sanliurfa cafe to a nearby hotel because he spotted an Islamic State “emir,” or prince, seated at a nearby table.

Sanliurfa’s proximity to the Syrian city of Raqqah, the self-styled capital of the Islamic State’s caliphate, has made it a hub for the group’s commanders, Syrians say. They come to this Turkish city to rest, visit their families, secure supplies — and now, many Syrians fear, to extend their campaign of persecution against activists and more-moderate rebels, such as Abu Issa.

“They have sleeper cells here, and they are armed,” said Khalaf Jurba, a veteran Syrian opposition activist and journalist living in Sanliurfa, also known as Urfa. “And now all of us are in danger because we are all on their list.”

Tourists also frequent the quaint and ancient city, where Nimrod is said to have hurled Abraham onto a burning pyre and where boutique hotels tucked in teeming bazaars offer glimpses of a bygone past. Americans were among those who showed up in tour groups in recent days. Journalists from around the world have converged on Sanliurfa to cover the fighting just across the border in the Syrian town of Kobane, where Kurdish militias aided by U.S. airstrikes are battling to repel the Islamic State.

The account of the attempted kidnapping of Abu Issa, given by friends and colleagues who helped him escape, reveals some of the dangers the Islamic State could pose far beyond the borders of Iraq and Syria. The details could not be independently confirmed, but the accounts of four Syrians who spoke to him separately after the incident coincide.

Abu Issa, who uses a nom de guerre as other rebels do to protect relatives inside Syria, could not be reached for comment. He has returned to war-ravaged Syria, said Abu Shujaat, a rebel colleague and friend who helped him escape. “He feels safer there than in Turkey,” he said.

A popular Syrian fighter and former farmer who had earned renown for his persistence in confronting the Islamic State, Abu Issa had been fighting in Kobane before traveling to Sanliurfa a week before the incident to rest and consult with fellow rebels, according to Abu Shujaat.

Late Friday afternoon, Abu Issa set off with his 20-year-old son, Ammar, for a meeting at the home of a fellow rebel, his colleague said. Their car was driven by Abu Maher, a trusted friend. Abu Maher was the media spokesman in Turkey for the men’s rebel battalion, the Liwa Raqqa al-Thuwar.

The driver took a diversion from their usual route, telling Abu Issa he was using a shortcut as he drove down a deserted alley. A car suddenly pulled in front of them, blocking their path. Another appeared behind them. A dozen or more men swarmed their vehicle, and Abu Issa and his son tried to run away. The men pulled pistols, shooting Abu Issa in the stomach and his son in his leg.

As the abductors tried to force him into one of the vehicles, Abu Issa realized that one of the men pushing him was Abu Maher, his driver and supposed friend, Abu Shujaat said.

“He was a traitor. He was secretly working for the Islamic State,” he explained.

The two captives were whisked toward the Turkish border town of Akcakale, adjoining the Syrian town of Tal Abiyad, which has been under Islamic State control for nearly a year. The kidnappers mostly spoke Turkish, though two also spoke Arabic, and they told Abu Issa they belonged to a Turkish mafia gang, Abu Shujaat said.

At the border, the abductors turned down a dirt road toward one of the many smuggling routes, nestled among cornfields and olive groves, through which Syrians sneak between their country and Turkey.

At a remote farmhouse just inside Turkey, the kidnappers made contact with their Islamic State counterparts waiting across the border. The militants demanded proof that the captive was Abu Issa, and the kidnappers took a video of him and sent it on a mobile phone. Abu Issa understood from the conversations that the two parties had reached a prior agreement that $500,000 was to be paid for delivering him to the extremists, Abu Shujaat said.

The Islamic State men did not intend to hand over the money, however. Without warning, a group of fighters surged across the border into Turkey and opened fire on the farmhouse, in an apparent bid to capture Abu Issa without paying.

Turkish border guards were alerted by the shooting and converged on the area. A helicopter with a searchlight appeared overhead, and a tank came into view. The Turkish gangsters scattered, as did the Islamic State fighters, and Abu Issa was left unguarded.

Barely conscious after bleeding for hours, he was rescued by a sympathetic local farmer who took him to the main road and helped him summon help from his rebel friends. They took him to a local hospital. Hours later, Abu Issa’s son, who was not the target, was let go.

The Syrians informed the Turkish authorities, who took statements and showed a great deal of interest in the identities of the Turkish gangsters, Abu Shujaat said. He added that they did not, however, pursue the allegedly complicit Syrian driver, Abu Maher, who has returned to his home in Sanliurfa.