Islamic State agents recruited students after urging them to join radical online forums, National Security Coordinator Yaw Donkor told state media.
Mr Donkor confirmed that two Ghanaians had travelled to join IS, the first such cases that have been reported.
Ghana has so far been unaffected by Islamist militancy.
Mr Donkor said there was "no reason to fear", adding that "only a handful" of Ghanaians had gone to join the militant group.
The wealth of IS meant that potential recruits had found the offers made to them by the militants' "irresistible", he added.
The recruits had travelled through Burkina Faso or Nigeria, before receiving training at a camp in Niger, and then making the onward journey to Turkey or Syria, the National Security Coordinator said.
