Three South Koreans were released in Turkey after being detained by Turkish security forces in an area near the border with Syria, South Korea's officials said Tuesday.

They were detained on charges of entering a restricted military area in the southern Turkish town of Elbeyli in Kilis province near the border with Syria, according to sources.

In Seoul, the foreign ministry identified them as two South Korean journalists and their Korean assistant and said they were questioned before being set free.

The arrest came as they were covering a story on an 18-year-old South Korean, identified only by his surname Kim, who disappeared during a trip to Kilis and was last seen leaving a hotel.

Kim, who was reported to have crossed the border into Syria, has since joined the Islamic State militant group and has been receiving training, South Korean lawmakers said in Seoul after being briefed in a close-door session by South Korea's spy agency last month.

The detention of the three South Koreans was first reported by the Turkish Dogan News Agency. (Yonhap)