A police drill simulating a bank robbery in Wuxi, Jiangsu province, caused panic because the exercise wasn't communicated to the public in advance, eastday.com reported on Thursday.
On Wednesday afternoon, a local netizen wrote on his micro blog that a bank robbery was made by two men who had knives and robbed some 100,000 yuan ($15,718).
The note was widely read and caused widespread concern.
The city's police then informed the public that the so-called bank robbery was a practical exercise.
Police said that the exercise was not announced in advance and that even the bank employees weren't aware of it.
On Tuesday, police in Chongqing shot dead a gunman who was suspected of robbery and murders near banks in Nanjing, Changsha and Chongqing in the last eight years.