The Boko Haram Islamist sect, which aims to impose sharia law across the country, claimed responsibility for the three church bombs, the second Christmas in a row the group has caused mass carnage with deadly bombings of churches. Security forces also blamed the sect for two other blasts in the north.
St Theresa's Catholic Church in Madala, a satellite town about 40 km (25 miles) from the center of the capital Abuja, was packed when the bomb exploded just outside.
"We were in the church with my family when we heard the explosion. I just ran out," Timothy Onyekwere told Reuters. "Now I don't even know where my children or my wife are. I don't know how many were killed but there were many dead."
Hours after the first bomb, blasts were reported at the Mountain of Fire and Miracles Church in the central, ethnically and religiously mixed town of Jos, and at a church in northern Yobe state at the town of Gadaka. Residents said many were wounded in Gadaka, but there were no immediate further details.
A suicide bomber killed four security officials at the State Security Service in one of the other bombs, which struck the northeastern town of Damaturu, police said. Residents heard two loud explosions and gunfire in the town.
A Reuters reporter at the church near Abuja saw the front roof had been destroyed, as had several houses nearby. Five burnt out cars were still smoldering. There were scenes of chaos, as shocked residents stared at the wreckage in disbelief.
"Mass just ended and people were rushing out of the church and suddenly I heard a loud sound: 'Gbam!' Cars were in flames and bodies littered everywhere," Nnana Nwachukwu told Reuters.
Father Christopher Barde, Assistant priest of the church, said: "The officials who counted told me they have picked up 27 bodies so far."
"I happen to also live close by the church. Help was very slow in coming to the injured," he said.
Police cordoned off the area around the church. Thousands of furious youths set up burning road blocks on the highway from Abuja leading to Nigeria's largely Muslim north.
Police and the military tried to disperse them by firing live rounds into the air with tear gas.
"We are so angry," shouted Kingsley Ukpabi, as a queue of hooting vehicles lined up behind his flaming barrage.
ATTACKS INCREASE
Boko Haram - which in the Hausa language spoken in northern Nigeria means "Western education is sinful" - is loosely modeled on the Taliban movement in Afghanistan.
It has emerged as the biggest security threat in Nigeria, a country of 160 million split evenly between Christians and Muslims, who for the most part live side by side in peace.
Boko Haram's low level insurgency used to be largely confined to northeastern Nigeria, but it has struck several parts of the north, center and the capital Abuja this year.
Last Christmas Eve, a series of bomb blasts around Jos killed 32 people, and other people died in attacks on two churches in the northeast.
The sophistication of the explosives it uses and the number of attacks it carries out have increased this year.
The sect was blamed for dozens of bombings and shootings in the north, and has claimed responsibility for two bombings in Abuja this year, including Nigeria's first suicide bombing, which killed at least 23 people at the U.N. headquarters.
Rights groups say more than 250 people have been killed by Boko Haram since July 2010.
At the church near Abuja, a wounded man whose legs were almost shattered to pieces by the blast was loaded onto a stretcher near an ambulance by security services.
"I'll survive," he said in a hushed voice.
The blast in Jos, a tinderbox of ethnic and sectarian tensions that sometimes sees deadly clashes between Muslims and Christians, was accompanied by a shooting spree by militants, who exchanged fire with local police, said Charles Ezeocha, special taskforce spokesman for Jos.
"We lost one policeman and we have made four arrests. I think we can use them to get more information and work on that," he said. Police found four other explosive devices in Jos, which they deactivated, he added.
President Goodluck Jonathan, a Christian from the south who is struggling to contain the threat of Islamist militancy, called the incidents "unfortunate" but said Boko Haram would "not be (around) for ever. It will end one day."
The White House condemned "this senseless violence and tragic loss of life on Christmas Day." A statement said: "We have been in contact with Nigerian officials about what initially appear to be terrorist acts and pledge to assist them in bringing those responsible to justice."
Vatican spokesman Father Federico Lombardi said the Vatican hoped "this senseless violence does not weaken the will of the Nigerian people to live peacefully and promote dialogue."
The attacks were condemned by a number of other countries, including Britain, France and Italy.
Gun battles between the security forces and Boko Haram killed at least 68 people Thursday and Friday in northern Nigeria, authorities and hospital sources said Saturday.
Boko Haram became active in about 2003 and is concentrated mainly in the northern Nigerian states of Yobe, Kano, Bauchi, Borno and Kaduna.
The group considers all who do not follow its strict ideology as infidels, whether they are Christian or Muslim. It demands the adoption of sharia, Islamic law, in all of Nigeria.