The National Investigation Agency (N.I.A.) has detained an adolescent from West Bengal who is suspected of having links with the Islamic State of Iraq and al-Sham (I.S.I.S.), an official said on Saturday. "The 19-year-old adolescent, belonging to Hooghly district, is a student of a private engineering college. We have detained him for interrogation. We suspect he may have links with the Islamic State of Iraq and al-Sham" the official said.