The electoral commissioner for Nigeria's second-most populous state, Kano, has died in a house fire with his wife and two children, his office told AFP on Friday.

Resident electoral commissioner Mukaila Abdullah presided over polls last weekend, in which opposition presidential candidate Muhammadu Buhari won overwhelming support in the northern state.

Buhari's All Progressives Congress (APC) also took all available seats in the parliamentary vote held at the same time.

"It is true we lost our commissioner to a fire outbreak in his house," said Lawan Garba, spokesman for the Independent National Electoral Commission (INEC) in Kano.

"He died along with his wife and two children. We have conveyed the bodies to his home town, Dutse (the capital of neighbouring Jigawa state), where he will be buried after Friday prayers."

The fire broke out at Abdullah's house in the upmarket Nassarawa area of Kano. Kano police spokesman Musa Magaji Majia said the fire broke out at about 4:30 am (0330 GMT) in an air conditioning unit in the living room.

Attempts were made to break inside the house and when police and security guards managed to enter, the family was found unconscious on the floor of the bathroom.

"They quickly removed them to Murtala Mohammed Specialist Hospital, where the doctor confirmed them dead ... from inhalation of hot and black smoke," Majia said. An investigation had been launched, he added.

Nigeria had been on edge in fear of a repeat of politically motivated post-poll violence but it failed to materialise.

Defeated candidate President Goodluck Jonathan was credited with defusing tensions by conceding to Buhari even before all results were declared.

In 2011, Kano was hit by two days of rioting after Jonathan's Peoples Democratic Party (PDP) won the state. Governor Rabiu Kwankwaso later defected to the APC.