Nigerian Islamist group Boko Haram has told the BBC it carried out the series of bombings after President Goodluck Jonathan’s inauguration on Sunday.
The worst incident was at an army barracks in the northern city of Bauchi in which at least 14 people died.
A sect spokesman said it was also responsible for killing the brother of the Shehu of Borno, one of Nigeria’s most important Islamic leaders.
The sect has been behind numerous recent assassinations in Borno state.
It is opposed to Western education and accuses Nigeria’s government of being corrupted by Western ideas.
Clashes in Borno’s state capital, Maiduguri, between the Boko Haram and the police in July 2009 left hundreds of people dead, mainly members of the sect.
For the past eight months, sect members have been fighting a guerrilla war in Borno, killing policemen and people they believe were helping the security services in the fight against them.
