Unidentified gunmen invaded the home of Aminu Saleh, former secretary to the Nigerian government, killing two police guards at the Azare, Bauchi state home used by the ex-official to receive visitors.
Sources said the attack might be linked to efforts by Mr. Saleh to bring together Muslim clerics and elders led by Dahiru Bauchi who have stated they are involved in a dialogue with Boko Haram.
The Boko Haram sect reportedly opposes dialogue with the Nigerian government on its behalf.
Mr. Saleh was at home at the time of the attack but was unharmed.
Last week, still unidentified gunmen shot and killed the former comptroller of prisons in the same city. Mr. Ibrahim Katagum died in hospital 24 hours after he was shot in the leg and stomach.