Security was tight in the city of Kaduna as the leader of a pro-Iranian Shiite group, Sheikh Ibrahim Zakzaky, was granted leave at his bail hearing to seek medical treatment in India.
The couple have been in detention since 2015.
Sheikh Zakzaky’s followers often clash with the police as they regularly protest to demand his release.
Last week, the government took the controversial decision to ban his Islamic Movement in Nigeria (IMN), accusing it of unleashing violence and being an “enemy of the state.”
It followed the death of more than 20 people, including a deputy commissioner of police and a journalist, in one protest in the capital, Abuja, in July.
In 2015, the IMN was accused of trying to assassinate the army chief of staff.
Sheikh Zakzaky was arrested and accused of murder, manslaughter, unlawful assembly and disruption of public peace – charges he denies.
His supporters say his health is deteriorating and that he needs to travel for medical care.