The International Criminal Court says that four of its staffers have been detained in Libya and is demanding their immediate release.

The war crime court says that the four were part of a mission in Libya sent to meet with deposed dictator Moammar Gadhafi's son and former heir apparent, Seif al-Islam, who was captured by revolutionary fighters in November.

In a statement Saturday, the court based in The Hague, Netherlands demanded their immediate release and said the four have immunity as members of the court's staff.