Two attacks on villages in Kaduna state Monday night claimed at least 38 lives while scores of several others sustained injuries.
The police in Bauchi state Sunday confirmed that at least 10 people were killed in an attack by gunmen who unleashed terror at a brothel.
In a statement released Sunday, the Nigerian leader expressed his administration's determination to bring the perpetrators to justice.
He commiserated with the families of those killed in the attacks and extended his sympathies to those who were injured or lost their property in "the wanton assaults on Bauchi and Kaduna states".
The government will also restore the fullest possible security to all parts of the country, the statement added.