Jos , Nigeria ( CNN ) -- A government official condemned Monday the series of Christmas Day attacks on churches in Nigeria that killed 35 people , blaming an extremist group that has claimed responsibility for similar attacks in the last two years . `` The latest mindless and cowardly attacks by Boko Haram members specifically directed at churches were premeditated , '' said retired Gen. Andrew Azazi , the national security adviser to President Goodluck Jonathan , in a statement . `` Only last week , five improvised explosive devices were recovered in five churches at Mubi in Adamawa State . '' The Boko Haram sect claimed responsibility for the attacks , government officials said . In the past , the group has targeted Christians and Muslims it considered insufficiently Islamic . In the bloodiest of Sunday 's attacks on churches in five cities , 32 people were killed as services ended at St. Theresa 's Catholic Church in Madalla in Niger State , Azazi said . Two people have been arrested , he added . Olusegun Okebiorun , controller-general of Nigeria 's fire service , said that , in addition to the fatalities , 65 people were wounded in Madalla , which is located west of the capital city of Abuja . Attacks in the central Nigerian city of Jos in Plateau State northeast of the capital followed the same pattern , Azazi said . Two blasts targeted the Mountain of Fire Ministries church in Jos , said journalist Hassan John , who witnessed the carnage . No one was killed in the bombings , but a police officer who got into a gun battle with attackers died of his wounds , John said , citing officials . Police arrested four people and recovered four unexploded devices , Nigerian state television reported . The cities of Kano , Damaturu and Gadaka were also struck Sunday , John said . Officials said three people were killed in the blast in Damaturu , a northern town in Yobe state , John said . Also in Damaturu , a police station and a state security building were bombed , said an aid worker who , citing security concerns , asked not to be identified . In Yobe , security forces stopped a vehicle that was carrying a bomb , which detonated , killing `` the criminals '' and three security operatives , Azazi said . `` We renew our appeal to all Nigerians that this is not a fight between security forces and some dissident elements , '' he said . `` It is a conflict between some misguided extremists in our midst and the rest of our society , because the victims are not confined to any ethnic boundary . We must cooperate to fish them out . And because our cause is just and our collective resolve is stronger , together we shall prevail . '' The blasts mark the second consecutive holiday season that bombs have hit Christian houses of worship in the west African nation . In 2010 , five churches in Jos were attacked on Christmas Eve . The blasts killed dozens in Jos , which lies on a faith-based fault line between the Muslim-dominated north and the mainly Christian south . CNN.com : Al Qaeda-linked group claims responsibility for bombing . In a statement issued late Sunday , Jonathan called the bombings `` a dastardly act that must attract the rebuke of all peace-loving Nigerians . '' In Washington , the White House said U.S. officials would help Nigeria pursue those behind `` what initially appear to be terrorist acts . '' `` We condemn this senseless violence and tragic loss of life on Christmas Day , '' White House spokesman Jay Carney said in a statement . `` We offer our sincere condolences to the Nigerian people and especially those who lost family and loved ones . '' U.N. Secretary-General Ban Ki-moon condemned the acts `` in the strongest terms , '' his office said in a statement . He expressed his condolences to the Nigerian people and reiterated a call `` for an end to all acts of sectarian violence in the country . '' Nigeria is Africa 's most populous nation and has the world 's sixth-largest Christian population -- about 80.5 million people as of 2010 , according to a report published this month by the Pew Forum on Religion & Public Life in Washington . That makes the country just over 50 % Christian , according to Pew . Boko Haram translates from the local Hausa as `` Western education is outlawed . '' The group has morphed into an insurgency responsible for dozens of attacks in Nigeria in the last two years . Boko Haram 's targets include police outposts and churches as well as places associated with `` Western influence . '' CNN 's Josh Levs , Richard Allen Greene , Esprit Smith , Karen Smith , Amir Ahmed and Hamdi Alkhshali contributed to this report .
Azazi blames `` misguided extremists '' 32 were killed in Madalla , a government official says . Government officials blame Boko Haram , which claims responsibility . President Jonathan slams the `` dastardly act ''