Sudan's military government has said two brothers of ousted President Omar al-Bashir have been arrested.
A military spokesman said this was part of a campaign to round up "symbols of the previous regime".
He added that irregular militias linked to the former ruling party had been brought under police or military control.
Earlier, the BBC was told by military sources and relatives of Mr. Bashir that the former president was himself in prison in the capital, Khartoum - six days after being overthrown.
Protesters say they will stay on the streets until the military generals now in charge hand over to a civilian-led administration.