A Muslim mob set ablaze a Catholic church frequented by Southern Sudanese in the capital Khartoum late on Saturday.
The incident appeared to be part of the fallout from ongoing hostilities between Sudan and South Sudan over control of an oil town on their ill-defined border.
Last week, South Sudanese troops seized Heglig, which the Southerners call Panthou, sending Sudanese troops fleeing. The Khartoum government later claimed to have regained the town.
Witnesses and a number of newspapers said several hundred people shouting insults at the South Sudanese set fire to the church. Fire engines could not put out the fire, they added.