A South Korean teenager who recently vanished in Turkey may have crossed the border into Syria to join the Islamic State, a Seoul official said Tuesday.

The whereabouts of the 18-year-old Korean, identified only by his surname Kim, have been unknown since he arrived in Turkey on Jan. 10. A local Turkish newspaper claimed   that he had exchanged e-mails with IS before traveling to the country.

Citing CCTV footage obtained by Turkish police, the ranking South Korean foreign ministry official said Kim took a van together with an unidentified man after meeting him in front of a hotel in Kilis, a city situated near the border with Syria.

Kim and the unknown man then got off near a refugee camp in Besiriye, about 18 kilometers southeast from Kilis, on that day, the official said, adding the van with a Syrian plate is an unlicensed taxi.

"Their whereabouts have not been known since they got off in Besiriye," the official said, asking not to be named. "There are also no records showing that they crossed the border at a checkpoint."

There has been no clear evidence so far supporting that Kim might have joined the IS group, but Seoul doesn't exclude such a possibility, the official said.

"The government cannot presuppose a possibility (that Kim might have joined the IS), but (if it is confirmed), it is a very worrisome situation," he said.

The disappearance of the Korean teenager has raised concerns that he might have traveled to Turkey to join the extremist Muslim militant group IS in Syria. Seoul has no diplomatic ties with Syria.

Police said that they found a few photos of IS members taken with their flag on the wallpaper of Kim's computer at home. Kim's mother told police that her son had exchanged emails with a Turkish friend named Hassan.

The Seoul Metropolitan Police Agency, which has been investigating the case, reportedly reached the tentative conclusion that there is a high possibility Kim sneaked into Syria to join the IS. The police agency is scheduled to unveil the results of its investigation on Wednesday.

Also on Tuesday, the foreign ministry decided to extend travel bans on six countries -- Iraq, Libya, Somalia, Syria, Afghanistan and Yemen -- by another six months.

The move came as the political and security situations in those countries are expected to remain unstable for the time being, it added. (Yonhap)