A local office of Nigeria's electoral body INEC has been set partially ablaze, the commission said Friday, the latest violence less than three months ahead of next year's presidential ballot.

Nigerians in February will elect a successor to President Muhammadu Buhari, who is stepping down after two terms in office.

Concerns have grown over recent attacks on the offices of the Independent National Electoral Commission (INEC), particularly in the southeast.

INEC spokesman Festus Okoye said the commission's office for Orlu area in Imo state was attacked.

He said the incident occurred on Thursday when the building, which was under repair following an earlier attack, was vandalised and partially set ablaze.

Okoye said three construction workers were kidnapped but were later freed.

"The damage would have been more extensive but for the quick response of the Nigeria Police which has deployed its personnel to the site," he said in a statement.

He lamented the frequent attacks on INEC facilities less than three months to the elections.

"This is one attack too many. The commission once again expresses its concern over the spate of attacks on its facilities and the negative consequences on our preparations for the 2023 general election."

Thursday's incident came less than a week after an INEC office and voting materials were torched in Ebonyi state, also in the southeast of the country.

INEC has recently warned of the threat of intensifying campaign violence ahead of the election, adding that it had tracked at least 50 attacks in the last two months.

Parliamentary and state elections will also be held in February.

Although no group claimed responsibility for the attack, southeast Nigeria has seen scores of assaults blamed on the outlawed separatists, the Indigenous People of Biafra (IPOB) group or its armed wing, the Eastern Security Network (ESN).

IPOB, which seeks a separate state for ethnic Igbo people in the southeast, has repeatedly denied responsibility for the violence.