Islamist sect Boko Haram
Chiemelie Ezeobi with agency report
Kneeling over a dusty grave on the outskirts of Abuja, 16-year-old Hope Ehiawaguan says a prayer, lays down flowers and tearfully tells her brother she loves him.
He was one of the 44 persons killed on Christmas Day last year when a member of the Islamist sect Boko Haram rammed a car packed with explosives into the gates of St Theresa's Church in Madalla, a satellite town of Abuja.
Boko Haram has killed some 3,000 in its campaign against western education in Nigeria. The battle they have waged against the country remains the biggest threat to its stability.
This Christmas, the police and military are expecting more trouble in the North. They've ordered security to be tightened, people's movements restricted and churches to be guarded.
“I feel safe," Ehiawaguan, in an interview with Associated Press (AP), says with uncertainty, when asked if she will come to church today.
"Not because of security here ... because we have a greater security in heaven," she says, wiping away her tears.
The blast in Madalla killed several people on the street and pulled down the church roof, condemning many of those trapped inside the burning building, including a seven-month-old boy.
A plaque listing the names of the members of the church who were killed has been placed above their graves. The twisted metal of the cars destroyed in the blast is still there.
“I only pray to God to give them a heart," Ehiawaguan says, when asked about her brother's killers.
Security experts believe Boko Haram is targeting worshippers to spark a religious conflict in the country.
The sect has also targeted mosques in the past and assassinated Islamic clerics who have questioned its insurgency. In the group's stronghold in the North-east, where most of its attacks occur, Muslims are equally at risk as Christians.
The fear for many is that more Christmas Day attacks could spark the sort of tit-for-tat sectarian violence between Muslims and Christians, which has claimed thousands of lives in the past decade.
"We have always insisted that Christians should not retaliate," said Sam Kraakevik Kujiyat, chairman of the Christian Association of Nigeria(CAN) in Kaduna State, one of the areas worst hit by inter-religious violence in recent years.
"But there is fear ... we know not everyone who says he is a Christian acts like one."
Churches were emptier than usual on Sunday in Kano and Kaduna, local residents said. Despite bolstered security in cities across the North, dual suicide bombers attacked the offices of mobile phone operators, Airtel and MTN in Kano last Saturday.
The bombers died but no civilian was killed.