An unidentified ransomware gang attacked the city of Knoxville, Tennessee’s IT network, forcing officers to shut down all systems on June 12.

According to local news station WVLT, the attack took place sometime between June 10–11, encrypting all files within the network infrastructure.

The attack forced workstations of the internal IT network to be shut down, which also disconnected internet access from the mayor’s infrastructure, public website, and even the Knoxville court.

The FBI is currently assisting in the investigation, although the identity of the ransomware group behind the attack has not yet been revealed.

The official statement from the Knoxville’s major

Knoxville mayor and former WWE wrestler Glenn Jacobs released a statement via the official Knoxville government Twitter profile:

“Cyber attacks can happen to anyone or any government no matter how good the defense is. In a lot of cases it’s not a matter of 'if' but a matter of 'when.' Our IT department has been in contact with the city and we stand ready to help if they need it.”

Knoxville joins a long list of cities in the United States that have been targeted by ransomware groups in recent months, along with Atlanta, Baltimore, Denver, New Orleans, and other smaller cities.

Cointelegraph recently reported that the NetWalker ransomware gang had attacked Michigan State University, or MSU. At the time, the gang threatened to leak students’ records and financial documents. However, the university’s officials have said that they will not pay the ransom.