Opposition groups in Sudan are accusing the military of a "lack of seriousness" in handing power to a civilian government after the ouster of president Omar al-Bashir.
The umbrella opposition group Declaration of Freedom and Change called for protests in capital Khartoum to continue.
Thousands of protesters, demanding that the military hand over power to civilian rule, have been staging a sit-in at the army's Khartoum headquarters.
The demonstrations began with the call for long-time president al-Bashir to go. The protesters got their wish on April 11, when the military deposed and arrested him.
But participants say the new military rulers are a continuation of al-Bashir's former regime and have clamoured for more concessions.
The Sudanese Professionals Association (SPA), one of the main protest organisers, on Sunday accused the interim military government of being an "extension of (al-Bashir's) regime" as it echoed the call for more demonstrations.
Earlier on Sunday, it emerged that investigators discovered more than $US7.5 million ($A10.5 million) in cash at al-Bashir's home.
A state prosecution employee told dpa a case into suspected corruption and money laundering had been opened and that searches would now target other members of al-Bashir's earlier leadership circles.
The employee, who asked not to be named, said searches would now target other members of al-Bashir's earlier leadership circles.
Investigators had found roughly 6.7 million euros ($A10.5 million), $US350,000 ($A500,000) and 5 million Sudanese pounds ($A147,000) during the search.
The employee, who did not wish to be named, said that the investigations were part of efforts by military leaders to expose the corruption of al-Bashir's system.
Several top politicians from the ruling National Congress Party have been arrested in recent days.
Australian Associated Press