The floods were the latest to devastate the poor region around Khartoum, where the White Nile and Blue Nile converge.
State-owned television broadcast footage of flood damage in the southern suburb of Mayo, where houses built of mud had been swept away.
There were no specific figures on the dead and homeless; television said dozens had died.
Majzoub Khalifa, Sudan's minister for social planning, promised prompt government action.
''We have found water completely surrounding a number of areas and a great many houses have collapsed,'' he was quoted as saying on television.
In recent months, floods have destroyed hundreds of homes in central and northern Sudan, leaving more than 15,000 homeless.
Last week, at least 17 people died in flash floods in a village north of Khartoum.
=A9 Copyright 1996 The Associated Press