Activists identified the youth as Sayed Taher Sayed Jaafar and reported that he was arrested along the causeway connecting Bahrain with neighboring Saudi Arabia.
There was no further information provided about the motives behind the arrest.
Earlier this month, the Bahrain Center for Human Rights (BCHR) revealed that at least 10 Bahrainis returning from their travels abroad were detained in the first half of 2018.
According to the rights group, many became victims of enforced disappearances while Bahraini authorities failed to produce arrest warrants.