ABUJA (Reuters) - Islamist militant group Boko Haram said it planted bombs that exploded on Christmas Day at churches in Nigeria, one of which killed at least 27 people on the outskirts of the capital.
Boko Haram, which wants to impose Islamic sharia law across the country split roughly equally between Christians and Muslims, has escalated its tactics this year and increased the sophistication of the explosives it uses.
St Theresa's Catholic Church in Madala, an Abuja satellite town about 40 km from the centre of the capital, was packed out when the powerful bomb exploded during a Christmas service.
"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."
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.
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 on the U.N. headquarters in August that killed at least 23 people.
Rights groups say more than 250 people have been killed by Boko Haram since July 2010.
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.
Police found two other explosive devices in Jos, which they deactivated and arrested one man.
Residents of the northeastern city of Damaturu also reported two blasts but there were no details immediately available.
CHAOS AND CARNAGE
A Reuters reporter on the scene of the explosion close to Abuja saw the large church's front roof had been destroyed in the blast, as had several houses near it. Five burnt out cars were still smoldering.
"The officials who counted told me they have picked 27 bodies so far," Father Christopher Barde, Assistant Catholic Priest of the church, said.
There were scenes of chaos after the incident.
"We are presently there, evacuating the dead and the injured, but unfortunately we don't have enough ambulances," National Emergency Management Agency (NEMA) spokesman Yushau Shuaib said initially by telephone. More ambulances came later.
"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.
"The blast occurred on the road by the church and not inside the church. I happen to also live close by the church. Help was very slow in coming to the injured."
President Goodluck Jonathan, a Christian from the south who is struggling to contain the threat of Islamist militancy, called the incident "unfortunate" but said Boko Haram would "not be (around) for ever. It will end one day."
The whole area around the church was cordoned off by police. 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.
The Vatican condemned the first blast. Its 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 in their country."
A witness at Jos saw one lightly wounded policeman from that explosion, but there were no reports of other casualties.
Last Christmas Eve, a series of bomb blasts around Jos killed 32 people, and others people died in attacks on two churches in the northeast of Africa's most populous nation.
Gun battles between the security forces and Boko Haram killed at least 68 people in two days of fighting in northern Nigeria, authorities and hospital sources said on Saturday.
Boko Haram has been blamed for scores of shootings and bombings in Nigeria's remote, semi-arid northeast, including a spate of attacks in the past few weeks.
On August 26, a suicide bomber struck the U.N. building in Abuja. At least 23 people were killed and 76 wounded by the bombing which gutted the ground floor and smashed almost all the windows. Boko Haram claimed responsibility on August 29, demanding the release of prisoners and an end to a security crackdown aimed at preventing more bombings.
The blast was the first known suicide bombing in Nigeria.
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.
Boko Haram followers have prayed in separate mosques in cities including Maiduguri, Kano and Sokoto, and wear long beards and red or black headscarves.
(Additional reporting by Tife Owolabi in Jos, Mike Oboh in Kano and a correspondent in Maiduguri.; Writing by Tim Cock