Amnesty International and many human right bodies has called on the Nigerian government to comply with a court ruling that calls for an end to the “unlawful” detention of Sheikh Ibrahim Zakzaky, the country’s top Shia Muslim cleric.

"Zakzaky is being unlawfully detained,” Amnesty Nigeria director Makmid Kamara said on Monday, adding that the Nigerian government would “demonstrate a flagrant -- and dangerous -- contempt for the rule of law" if it ignored a December ruling by an Abuja court, which called the detention of Sheikh Zakzaky and his followers illegal and unconstitutional.

The Nigerian court has imposed a 45-day deadline for the release of Sheikh Zakzaky and hundreds of his supporters. The deadline expires later on Monday.

Sheikh Zakzaky, who leads the Islamic Movement in Nigeria (IMN), was arrested more than a year ago during raids by the Nigerian army on peaceful gatherings of IMN members in the northern city of Zaria. Human rights groups say nearly 350 IMN members were killed in the army raids. The Nigerian military has rejected the death toll.

In mid-December 2015, the Nigerian army attacked the northern city of Zaria and killed hundreds of IMN supporters. A large number of others including wounded Sheikh Zakzaky and his wife have been in detention without any trial ever since.