A Korean teenager who went missing in Turkey earlier this month had deliberately planned his trip and disappearance near the Syrian border, the police said Wednesday, raising the possibility of his involvement with the Islamic State militant group.

The 18-year-old tourist from Seoul, surnamed Kim, vanished on Jan. 10 after leaving a hotel in the border town of Kilis, according to the Seoul Metropolitan Police Agency and Foreign Ministry. He initially set foot in Istanbul on Jan. 8 and flew to the southern city of Gaziantep before reaching Kilis by car the next day with another Korean surnamed Hong, who reported his disappearance to the Korean Embassy on Jan. 12.

After questioning his family and Hong, the police concluded that Kim appeared to have willingly gone to the border region as he had been in contact with a Turkish man via social media, arranged his entire itinerary on his own and concealed the purpose of the trip to Hong and his parents.

“So far we have not discovered any link to a possible abduction or disappearance,” Chung Jae-il, head of the agency’s first international crime investigative unit, told a news conference in Seoul.

“Although we unearthed a multitude of materials suggesting his interest in the IS, we cannot confirm whether he has actually joined it.”

Since October, Kim had chatted with a Twitter user based in Turkey about ways to join the extremist group, the police said. The man gave Kim the phone number of a presumed IS member in Istanbul named Hassan who would “help” him via Surespot, an encrypted messenger service that directly links users’ devices to transmit conversations to boost security.

In one Twitter post, a user purported to be Kim said he “wanted to join” the militant group. In another, he wrote he was “ready” to travel to the Eurasian country. He also wrote he sought to “leave my country and family” and “just want to get a new life.”

The police also found more than 50 images on his computer of IS fighters and flags and Muslim women, as well as evidence that he had looked up such words as the IS, Islam, Turkey and Syria more than 500 times over the past year, with 65 related websites bookmarked on his browser.

On Tuesday, Foreign Ministry officials here said that Kim had ridden with a local man in a vehicle with Syrian license plates that was being used as an unregistered taxi, citing CCTV footage and the Turkish police.

The driver told Turkish police that he dropped them off after about 25 minutes near a Syrian refugee camp in Besiriye, some 18 kilometers east of Kilis and 5 kilometers from the frontier. He said the two men had not conversed during the ride, apparently to avoid revealing their identities.

But the video failed to help identify the other passenger, who the driver said spoke Arabic and was “ordinary” though he could not specify his nationality.

With Turkey and Syria sharing a porous border stretching some 900 kilometers, many foreign terrorist fighters travel from Istanbul to Kilis via Gaziantep to sneak into Syria, experts and activists say.

If he has indeed joined the group, Kim would be the first confirmed Korean IS fighter. A Saudi Arabian IS member said in a media interview in September that the group consisted of fighters of various nationalities, including Koreans, but Seoul officials have dismissed the claim as unreliable.

Ankara said it has barred entry to Turkey of more than 7,200 people who were thought to be seeking IS membership, while deporting nearly 1,200 would-be jihadists.

By Shin Hyon-hee (heeshin@heraldcorp.com)