Lagos
A series of explosions were reported Sunday across Nigeria, including one at a Catholic Church near that capital that killed at least 25. A radical Muslim sect, Boko Haram, has claimed responsibility.

At least three of the five explosions appeared to target churches during Christmas services, according to media reports. One explosion struck St. Theresa Catholic Church in Madalla, a town about 25 miles north and west of the capital, Abuja.

Rescue workers there recovered at least 25 bodies and officials continued to tally those wounded in various hospitals, said Slaku Luguard, a coordinator with Nigeria’s National Emergency Management Agency.

His agency has acknowledged it did not have enough ambulances immediately on hand to help the wounded. Mr. Luguard also said an angry crowd that gathered at the blast site hampered rescue efforts as they refused to allow workers inside.

“We’re trying to calm the situation,” he said. “There are some angry people around trying to cause problems.”

Witnesses told Reuters that St. Theresa’s Church was filled for the Christmas service when the bomb exploded.

“I heard the blast. My house shook,” a resident, Tony Akpan, told Reuters. “I came out to the front of the church to see what was happening. I counted 19 bodies myself, many of them mutilated, and 5 destroyed vehicles.”

Another witness, Timothy Onyekwere, told Reuters that he was in the church with his family when the bomb exploded.

“I just ran out. Now I don’t even know where my children or my wife are,” Mr. Onyekwere said. “I don’t know how many were killed but there were many dead.”

Some said the blast was inside and others thought it came from just outside the church.

A Boko Haram spokesman, who identified himself as Abu Qaqa, claimed responsibility for the attacks in statements to the media. In the last year, Boko Haram has carried out increasingly bloody attacks in its campaign to install strict Shariah or Muslim law across Nigeria. The same group also claimed responsibility for a series of Christmas Eve bombings a year ago in the northeast city of Jos that left at least 32 dead and 74 wounded.

A second explosion on Sunday was near the Mountain of Fire and Miracles Church in Jos, a government spokesman Pam Ayuba, said. Mr. Ayuba said gunmen later opened fire on police guarding the area, killing one officer. Two other bombs were found in a nearby building and disarmed, he said.

“The military are here on ground and have taken control over the entire place,” Mr. Ayuba said.

Jos is on the dividing line between Nigeria’s predominantly Christian south and Muslim north. Thousands have died in communal clashes there over the last decade.

News agencies reported at least three other explosions, two in the city of Damaturu and another targeting a church in Gadaka. A police commissioner Tanko Lawan, said in Damaturu that suicide car bombing occurred around noon and was aimed at the headquarters of Nigeria’s secret police in the area. He declined to comment further, saying police had begun an operation to attack suspected Boko Haram sect members.

In Rome, the Vatican denounced the attacks as a sign of “cruelty and absurd, blind hatred” that shows no respect for human life. A Vatican spokesman Rev. Federico Lombardi said the Catholic church was praying for all Nigerians confronting “this terrorist violence in these days that should be filled with peace and joy.”

The United States Embassy in Nigeria’s capital of Abuja had issued a warning Friday to citizens to be “particularly vigilant” around churches, large crowds and areas where foreigners congregate.

Several days of fighting in and around the northeastern city of Damaturu between the sect and security forces already had killed at least 61 people, authorities said.

In the last year, Boko Haram has carried out increasingly bloody attacks in its campaign to implement strict Shariah law across Nigeria, a nation of more than 160 million.

Boko Haram claimed responsibility for a Nov. 4 attack on Damaturu, Yobe state’s capital, that killed more than 100. The group also claimed the Aug. 24 suicide car bombing of the United Nations headquarters in Nigeria’s capital that killed 24 people and wounded 116 others.

The sect came to national prominence in 2009, when its members rioted and burned police stations near its base of Maiduguri, a dusty northeastern city on the cusp of the Sahara Desert. Nigeria’s military violently put down the attack, crushing the sect’s mosque into shards as its leader was arrested and died in police custody. About 700 people died during the violence.

While initially targeting enemies via hit-and-run assassinations from the back of motorbikes after the 2009 riot, violence by Boko Haram now has a new sophistication and apparent planning that includes high-profile attacks with greater casualties.

Boko Haram has splintered into three factions, with one wing increasingly willing to kill as it maintains contact with terror groups in North Africa and Somalia, diplomats and security sources say.

Sect members are scattered throughout northern Nigeria and nearby Cameroon, Chad and Niger.