Much of Sudan's population lives in sprawling slums around the capital without running water or electricity, having fled the regional conflicts that have beset Africa's biggest country for decades. Few can afford medical treatment.

"This is intended to try to help the poor," the governor of Khartoum state told Reuters, explaining the decision to offer free surgery to those without the money to pay for it. He said the health budget was 23 percent of the total state budget.

Khartoum's revenues have surged since a 2005 deal to end a north-south war, although conflict continues in the western Darfur region. Oil production, mostly from wells in the south, has risen to 500,000 barrels a day while global prices have soared.

Khartoum, once a quiet and dingy city, has been transformed by the new money, with new roads, bridges and street lights.

According to the International Monetary Fund, Sudan's gross domestic product was estimated to have grown over 11 percent in 2007 and is forecast to increase by more than 10 percent this year.