The six were taken after Friday prayers in the capital, Baghdad.
Jamal Ibrahim, a spokesman for Sudan's Foreign Ministry, told Aljazeera: "The captured are the embassy's second secretary, Abd al-Munaim al-Toum, and five other local employees at the embassy.
"We will inform the families of the hostages. Unfortunately, we have not had enough information about the abduction."
Ibrahim added that the Sudanese were not among people usually targeted by armed groups in Iraq.
He said: "We appeal to the captors to release them yet we have no idea about the group who kidnapped them."
An unidentified caller has contacted the Sudanese embassy to claim responsibility for the capture.
Ali Karti, Sudan's minister of state at the foreign ministry, appealed to the captors to be rational and release the captives.
"Sudan has stood with our brothers, the Iraqi people, during their crisis"
Sudan's minister of state, foreign ministry
Karti said: "We appeal to the captors, who have carried out such an unacceptable action, to be rational and to remember Iraq-Sudan relations, as Sudan has stood with our brothers, the Iraqi people, during their crisis."
Aljazeera reported that the Sudanese government was in contact with Jordanian and Iraqi officials in an attempt to release the men.
Karti reconfirmed this, saying: "Contacts are currently held with sides in Amman and Baghdad. We will give more comments when these contacts come up with something."
Aljazeera also reported that four Iraqis were killed and eight others injured on Friday when a bomber wearing an explosives belt detonated himself inside a Shia mosque in the Balad Roz area east of Baquba.