Israel’s Ynet News site reports that three soldiers and one civilian have been arrested on suspicion of working for Iranian intelligence while they were minors, according to Al Jazeera.

They are accused by domestic security agency Shin Bet and the Israeli police of filming sensitive locations, including a training facility belonging to the Israeli air force, where some of them studied.

Authorities in Israel say several of them approached Iranian agents of their own free will.

They were arrested in March, Ynet reports, but had indictments filed against them by the Attorney General’s Office today.