NEW DELHI — Indians awakened to confusion Wednesday as banks and ATMs remained closed after the government withdrew the highest-denomination currency notes overnight to halt money laundering in a country where many in the poor and middle-class still rely mainly on cash.

Roadside vegetable sellers, kiosks selling biscuits and tea, small mom-and-pop stores selling groceries, all saw a sharp drop in customers on Wednesday, the day after Prime Minister Narendra Modi’s surprise televised announcement.

As of midnight Tuesday, all 500- and 1,000-rupee notes had no cash value. People holding the discontinued notes can deposit them in banks and post office savings accounts before the end of the year. But anyone making large bank deposits might invite the unwelcome attention of Indian tax authorities.

Finance Minister Arun Jaitley told state-run news channel Doordarshan that if the money deposited in banks was illegal then the depositors would find themselves in “trouble.”

Banks and ATMs were likely to stay closed Thursday, too, to help prepare for the swarms of people who will rush to deposit their 500- and 1000-rupee bills and withdraw money to spend once they reopen.