On Friday mornings the streets of Khartoum are empty, as Muslims from Sudan's Arab and Islamic north pack mosques throughout the city. Prayer leaders read from the Koran, as the faithful spill onto the streets in long rows.
One could be forgiven for thinking that Sudan was an entirely Islamic country.
But on Sunday morning in Khartoum, the streets are largely empty again, as a myriad of Christian faiths pack churches and speak to God in their way. Churchgoers - almost all of them ethnic Africans from southern Sudan - loudly sing out hymns of love and faith to African rhythms.
One could also be forgiven for thinking that Sudan was an entirely Christian country.
The apparent religious freedom seems contrary, however, to accusations that Sudan's Islamic regime is bent on imposing Islamic law throughout the country - a widely held belief in the south that has helped spark 15 years of civil war.
"Torture, religious persecution, slavery, and forced imposition of sharia law on Sudanese throughout the country are pervasive and well documented," said Susan Rice, head of the US State Department's Bureau of African Affairs, in a statement before House subcommittees as recently as July.
But Sudan government officials deny they intend to spread Islam by force to the south. They say that sharia, the Islamic law that prevails in the north, will not be applied there.
"If we wanted to Islamize Sudan, we would start doing that here," says Foreign Minister Mustafa Osman Ismail, pointing out several Christian churches from his high office window. "But we don't. It is a big lie."
Some church officials praise Mr. Osman for his personal efforts to bring Sudan's Muslims and Christians together. But they add that patterns of harassment by security forces continue, despite promises made to Pope John Paul II during a 1993 visit.
At that time, Sudan's bishops warned the pontiff that he would be shaking hands with killers of Christians. The pope nevertheless led a mass for tens of thousands of southern Sudanese, most of them part of the large population of those displaced by the civil war who now live in the southern part of the capital, Khartoum.
"Things have not really changed," says a Christian priest, who asked not to be identified further. "Here, southern Christians are like a bone in the throat of Arab Muslims. So when they talk about tolerance, they want to uproot Christianity."
Suspicions are many. After a Sunday service, an old southern man approaches and strikes up a conversation with a visitor. Almost immediately, a young woman draws the visitor away and warns in a whisper: "He is with the security."
Though conditions have improved to a degree in the past several years - in keeping with Sudan's stated policy of mutual coexistence - not all elements of the regime seem to be on board.
The Catholic Club was occupied by police and security forces last year. Now the cross and title have been painted over. At a St. Matthew's Church service, parishioners were handed "call to prayer" leaflets that detailed the arrest of two Catholic priests on charges of taking part in a series of June 30 explosions. Their rooms were ransacked by police units.
A worker from the Catholic Bishop' Conference was picked up for the same reason, released, and then shortly after re-arrested.
"This kind of armed harassment," noted Khartoum Auxiliary Bishop Daniel Adwok in the leaflet, "appears to be part of an attempt to discredit the Catholic Church here in northern Sudan."
The leaflet began with a biblical quote from the book of Mark:
"Did you have to come with swords and clubs to capture me, as though I were a criminal? Day after day I was with you teaching ... and you did not arrest me. But the scriptures must come true."