The BICICI, a local subsidiary of France's BNP Paribas bank, said it had temporarily suspended all Ivory Coast operations in a statement published on its website Monday.
"We are no longer capable of assuring that our activities are carried out with sufficient judicial and financial security for our clients, nor physical security for our employees," the statement said.
Tuesday is a national holiday in Ivory Coast, so the number of banks that had closed could not be determined. But a bank official, who asked to not be identified because he is not authorized to speak to journalists, said more banks would close during the coming week.
Officials condemned the measure on state television Monday evening, saying BICICI and U.S. bank Citibank were punishing the Ivorian people by closing.
Citigroup said in a statement its offices in the Ivory Coast were closed Monday "in light of recent developments," and remained closed during the holiday on Tuesday.
"We continue to monitor the situation closely, remaining in contact with our employees, whose safety is our paramount concern, and our clients, who we are working with through this difficult situation," the statement added.
West African regional bank Ecobank has shut down its automatic banking machines, but employees at several locations said it was because of computer problems.
Justin Katinan Kone, the budget minister in the government of incumbent leader Laurent Gbagbo, accused the BICICI of timing the closure to coincide with the payment of public service salaries, but assured Ivorians that "every measure has been taken with other banks to assure the payment of salaries and the continuity of bank services."
The closures spread fear that cash could run out in the West African nation that is gripped by a political standoff between Gbagbo, who refuses to give up power after a November presidential election, and his opponent Alassane Ouattara. International organizations say Ouattara won the November poll, and the results were certified by the U.N.
The regional central bank of West African states, known by its French acronym BCEAO, endorsed Ouattara's victory and replaced a key Gbagbo ally at its head last month in a move to cut off Gbagbo's access to state coffers. Gbagbo retaliated by seizing the central bank's local offices and all of the cash they had, though the electronic system that manages international financial transfers was shut down by the bank's head office in Dakar, Senegal.
Banking has continued since then, though at a slowed pace because commercial bank transactions are no longer underwritten by the central bank and every check has to be manually cleared before it can be cashed.
The delays could adversely affect business in the world's largest producer of cocoa and send ripple effects through the region, which relies on Ivory Coast's ports for food and construction supplies.
Last week, the BCEAO threatened criminal proceedings against all banks that continued to work with local branches in Ivory Coast, now run by employees who answer only to Gbagbo's government.
Gbagbo was able to pay civil servant salaries in December and January, but it's unclear how deep his financial reserves are or how long he will be able to keep the country running.
In January, Ouattara declared a one-month moratorium on cocoa exports in an effort to sever one of Gbagbo's last sources of revenue
Most major international cocoa exporters have complied with Ouattara's measure, but the cocoa is stockpiled in humid warehouses and could go bad if it is not exported soon.