SEOUL (Yonhap) — A South Korean teenager who vanished in Turkey last month has joined the Islamic State (IS) militant group and has been receiving training, lawmakers quoted South Korea’s national spy agency as saying Tuesday.

The 18-year-old, identified only by his surname Kim, disappeared on Jan. 10 during a trip to the southern Turkish town of Kilis and was last seen leaving a hotel.

He was reported to have crossed the border into Syria voluntarily to join the extremist group.

“Kim has joined IS and although the location hasn’t been confirmed, he has been receiving training,” lawmakers quoted an official of the National Intelligence Service (NIS) as saying during a meeting of the parliamentary intelligence committee.

“The agency said it has confirmed that Kim has been staying in a training camp,” a lawmaker said, requesting anonymity, without further elaboration.

It is the first time that the government officially confirmed Kim’s joining of the rogue group, shocking the country, which has never seen such a case before.

The foreign ministry said it has “no intelligence on his whereabouts,” while stressing that it “has been closely in cooperation with the Turkish government on the matter.”