Several people protesting in the Chinese city of Zhengzhou over the freezing of deposits by some rural-based banks said they were injured when heavy-handed security personnel dispersed the crowd.
The banks froze millions of dollars worth of deposits in April, telling customers they were upgrading their internal systems.
The banks have not issued any communication on the matter since, depositors said.
None of the banks has responded to emails and telephone calls seeking comment.
Chinese media has reported that the frozen deposits could be worth up to $1.5 billion and authorities are investigating the three banks.
Anguished depositors have staged several demonstrations in the city