(CNN) -- Four men on death row for killing two U.S. international aid employees in Sudan escaped from prison in Khartoum, a State Department spokesman said Friday.
P.J. Crowley said the four, sentenced to death for the 2008 murders of John Granville and Abdelrahman Abbas Rahama, escaped from Kober prison.
"The United States government expects that Sudanese authorities will apprehend these convicted murderers and ensure that justice is served for the men killed and their families," he said.
Granville's sister Katy Granville McCabe said that a U.S. attorney told the family Friday morning about the escape. McCabe said she was told the four broke out of jail Thursday night and shot and killed a Sudanese police officer a roadblock.
Granville, 33 and a top official of the U.S. Agency for International Development in Sudan, and Rahama, 39 and Granville's driver, were shot and killed January 1, 2008, as they returned from New Year's celebrations.