Guinea's military junta, which seized power over the weekend, said on Thursday that it has ordered the central bank and other banks to freeze all government accounts.
On Sunday a group of special forces soldiers said they ousted President Alpha Conde over concerns about poverty and endemic corruption.
The banking freeze was aimed at "securing state assets", a junta spokesman announced on the national broadcaster.
A mining boom propelled strong economic growth during Conde's decade in power, but surveys suggest Guineans thought corruption has increased in recent years, while dissatisfaction with the economy and living conditions has also risen.
A delegation of West African leaders was due in Guinea on Friday to assess the situation following the coup that has raised fears of a backslide towards military rule in the region.