Votes are being counted in 29 of Nigeria’s 36 states, after polls to elect state and local representatives.
The state elections, which took place on Saturday, came two weeks after the presidential election.
In oil-rich Nigeria, some state governors control budgets larger than those of neighbouring countries – so these seats are often keenly contested.
President Muhammadu Buhari beat his main rival Atiku Abubakar on 23 February, securing a second term.
Results for the state elections are expected to start coming in later on Sunday.
Seven states – Kogi, Bayelsa, Ekiti, Osun, Ondo, Edo and Anambra – did not hold elections because their governors have not finished their four-year terms.
In last month’s poll, Mr Buhari’s All Progressives Congress (APC) got 15.2 million votes across the country, while Mr Abubakar’s People’s Democratic Party (PDP) received 11.3 million. There are 73 million registered voters.
The APC won 19 states, while the PDP secured 16, plus the capital, Abuja.
Mr Abubakar said the election was a “sham” and was not free and fair. He has since filed a petition challenging President Buhari’s win.