The deadly Christmas Day bombings in northern Nigeria by shadowy Islamist sect Boko Haram have stoked fears of sectarian conflict in Africa's top oil producer and most populous state.
The Islamist group claimed three bomb attacks in churches on Christmas Sunday, including one that killed 27 worshippers in a Catholic church just outside the capital Abuja. More than 40 people were killed in the bombings.
On Wednesday this week, seven people were wounded after assailants threw a bomb into a madrassa in southern Nigeria's Delta state, raising tensions between Muslims and Christians.
"For hundreds of years, there's been a race, 'Islam versus Christianity' in Africa," Christof Sauer from the International Institute for Religious Freedom (IIRF) told Deutsche Welle. "Just like Sudan, Nigeria lies exactly on the fault line of this conflict."
Sauer said there are reports of regular religiously-motivated attacks in Africa with people at times being pulled from buses and being asked their faith. "Depending on the answer, some are beheaded," Sauer said.
According to a 2009 study by the IIRF, 70 percent of the world's population live in countries where freedom of religion is severely restricted.
There are no studies about how many of the world's estimated two billion Christians suffer religious harassment. But in September this year, Kurt Cardinal Koch, president of the Pontifical Council for Christian Unity, said Christians made up 80 percent of those suffering religious persecution.
Regional differences in Asia
And the numbers of those facing religious oppression have climbed in recent years, according to several studies. They also point to strong regional differences. In Asia - particularly in Afghanistan and increasingly in Pakistan - religiously-motivated "revenge attacks" are on the rise.
In parts of Indonesia, said Sauer, Christians face attacks by militant Hindus and Muslims.
In Saudi Arabia, Christians face strong curbs in practicing their faith. Private church services are banned as is converting from Islam to Christianity.
In India too, Christians, particularly in poor tribal belts, face periodic attacks by militant Hindu groups for converting to Christianity.
In several countries, which were part of the former Soviet Union, strict laws curtail religious freedom in an attempt to curb the influence of Islam.
The non-governmental organization "Open Doors" estimates that state-backed repression of religious freedom is particularly high China, Iran, Myanmar, Turkey, Vietnam and North Korea.
"We believe that 70,000 Christians in North Korea are in labor camps," Sauer said. "And in Iran, the police have summoned Christians during Christmas to raise pressure against organizing festivities."
In recent months, the situation in the border between Asia and Africa has taken a turn for the worse. In 2011 alone, the Arab Spring prompted tens of thousands of Christians, particularly in Egypt, to flee. Observers expect a similar development in Syria if the regime of President Bashar al-Assad were to fall.
Deadly cocktail in Africa
But the situation is by far the worst in West Africa where a deadly mix of religion and politics undergirds many of the conflicts.
Islamist group Boko Haram - suspected of links to al Qaeda - made global headlines in August 2011 when a suicide bomber drove a car into the headquarters of the United Nations in Abuja, killing 24 people.
"In Nigeria, the conflicts can be traced to a dangerous mix of poverty, fanaticism and frustration," Emmanuel Ogbunwezeh, Africa expert at the International Society for Human Rights, told Deutsche Welle. "And this explosive cauldron boils over every now and then."
Nigeria provides the perfect base for Boko Haram, whose name translates as "Western education is sinful" in the Hausa language of the region, to carry out its attacks.
Nigeria's 160 million people are roughly divided between Muslims and Christians. Old tribal rivalries and economic interests serve to fuel religious hatred, especially in the country's poorer, Muslim-dominated northern areas.
It's all about power and "destabilizing the Christian-dominated richer south," Ogbunwezeh said, adding that the stability of the entire continent is at stake. "If you want to control Africa, you first need Nigeria as a military power and an oil exporter," he said.
Ogbunwezeh is pessimistic about the future, saying the country is on the brink of civil war. "If nothing changes there will be no Nigeria in 10 years," he warned.