By Do Je-hae



Five foreigners who have ties to the Islamic State (IS) have been denied entry into Korea, according to the National Intelligence Service (NIS), Tuesday.



They were possessing ammonium nitrate, the main ingredient for bombs.



The spy agency revealed the case during a National Assembly audit session, according to Reps. Lee Chul-woo of the ruling Saenuri Party and Shin Kyoung-min of the New Politics Alliance for Democracy.



The agency did not reveal how the five foreigners were handled after the entry denial.



The agency said that Korea was no longer free from terrorist attacks, citing the case.



The NIS also reported additional cases of Koreans attempting to join the terrorist group. Authorities have barred them from leaving the country.



"The two Koreans who attempted to join the IS have been forbidden from departing the country and their passports have been cancelled," Lee said, citing the NIS.



The NIS was unable to provide information on the whereabouts of the first Korean to have joined the IS militants earlier this year.



The NIS was able to trace his whereabouts until late May, but since then lost track of him.



Identified by authorities only by his surname Kim, the 18-year-old home-schooled boy disappeared in Turkey and crossed into Syria to join the militant group earlier this year.



Latest news reports have speculated that the teenager might have been killed during a recent strike by U.S and Jordan joint forces in Syria's Ar-Raqqah Province.



The terrorist group has established a stronghold in Ar-Raqqah Province since July 2014.



The teenager made headlines when police authorities confirmed in January that he had crossed the Turkish border into Syria to voluntarily join the militant group. He first left Korea on Jan. 8 on his first overseas trip and arrived in southern Turkish town of Kilis, about 5 km away from the Syrian border. He disappeared after arriving at a camp for Syrian refugees near Besiriye, a Turkish town some 18 km east of Kilis.



