In the early hours of 22 April 1990 a faction of mostly junior officers led by Major Gideon Gwaza Orkar (Tiv, Benue) and Major Saliba Mukoro (Urhobo, Delta) attacked Dodan Barracks (then the seat of government), Bonny Camp, the Federal Radio Corporation of Nigeria Ikoyi, and the residence of President Ibrahim Babangida. Babangida escaped through a perimeter gate while his ADC Lt-Col U.K. Bello was killed defending him.
Orkar's broadcast on FRCN — the most ideological coup speech in Nigerian history — announced the 'temporary excision' of Sokoto, Borno, Kano, Katsina and Bauchi States from the federation, citing Northern oligarchic capture of national resources. Loyalist forces under Brigadier Sani Abacha retook the city by mid-morning.
42 plotters were tried by Special Military Tribunal under Major-General Ike Nwachukwu and executed by firing squad at Kirikiri Prison on 27 July 1990 — the largest mass execution in Nigerian military history. The coup's failure marked the peak of Babangida's grip on power and the radicalisation of military-officer politics that would culminate in the 1993 annulment and the Abacha years.