A man was shot at the neck and lower abdomen on Saturday during a wedding ceremony in the Nuba Mountains.
Sources say the man died in the local hospital on Sunday while receiving treatment, Radio Voice of Peace reports.
Another one sustained injury at the leg, the sources say.
Ayman Mustafa Kuwa, one of the sources says the deceased was the best man of the bridegroom.
Speaking in Arabic, he adds that the man who shot the deceased was emotionally moved.
Mustafa says the gunman is an old soldier who neither drinks alcohol nor smokes.
Radio Voice of Peace could not reach the police for further comments on any information about arrest or escape of the gunman.