The commission was about to begin the distribution of permanent voters’ cards to newly registered voters on Monday.

It was the second attack on the Independent National Electoral Commission (Inec) in Imo state in just over a week.

The police said the gunmen came in several vehicles. They stormed the Inec office at about 03:00 local time in a deadly raid. They fired sporadically and threw dynamite and petrol bombs, damaging part of the building and vehicles.

Police spokesman Michael Abattam told the BBC that one policeman was killed while three of the attackers were shot dead.

“Another policeman was also injured as they were exchanging bullets with the assailants. Two of the attackers have been arrested,” he said.

Rising insecurity, especially attacks on Inec facilities, in the south-east have raised questions over the ability of the security forces and the electoral commission to conduct a successful poll next February.