The city of Amagasaki in western Japan said Thursday that it has lost a USB flash drive containing personal information on all of its roughly 460,000 residents.

The lost data included the residents' names, addresses and dates of birth, as well as the bank account numbers of welfare-receiving households, among other information. There is no evidence of data being leaked so far, according to the city in Hyogo Prefecture.

An employee of a company commissioned to assist the city's rollout of COVID-19 relief funds lost a bag that had the flash drive inside after drinking and dining at a restaurant on Tuesday, the city said.

The employee reported to police on Wednesday. The data was encrypted and protected with a password, according to the city.

"We will thoroughly ensure security management when handling electronic data," the city said in a statement. "We will work to regain our residents' trust by heightening awareness of the importance of protecting personal information."