Islamist group Boko Haram has claimed responsibility for the series of bomb blasts that occurred in Bauchi, Abuja and Zaria after President Goodluck Jonathan’s inauguration last Sunday.
The worst incident was at an army barracks in Bauchi in which at least 14 people died.
The sect’s spokesman said it was also responsible for killing one Abba Anas Ibn Umar Garbai,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.
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.
Sect spokesman Abu Zayd told the BBC’s Hausa Service that serving members of the Nigerian army had been used to carry out the bombings in the Bauchi barracks on Sunday.
Some soldiers wanted to join the sect and had been used as a way of testing their loyalty to Boko Haram, he said.
But Nigerian army spokesman Brig-Gen Raphael Isa rejected the allegation.
“It is not correct. Let him publish the names of those pledging loyalty to Boko Haram,” he told the BBC News website.
“This is not a banana republic. We are one army united and very very loyal,” he said.
Mr Zayd said the sect was also behind the killing of Abba Anas Ibn Umar Garbai, who was killed by gunmen outside his home in Maiduguri on Monday evening.
”We are the ones responsible for the killing of the junior brother of the Shehu of Borno,” he said.
The Shehu of Borno is one of Nigeria’s most prominent religious figures – second only to the Sultan of Sokoto, the spiritual leader of Nigeria’s Muslims.
“As we always say, these traditional institutions are being used to track and hunt us, that is why we attack them,” Mr Zayd said.
“We are doing what we are doing to fight injustice, if they stop their satanic ways of doing things and the injustices, we would stop what we are doing.”
Officials say 16 people died in the explosions in Bauchi, Zuba, Zaria, hometown of Vice-President Namadi Sambo, and Maiduguri.
The first attack came only hours after President Jonathan was sworn in for his first full four-year term of office in the capital, Abuja.