The city of Atlanta’s computer network has been the victim of a ransomware cyberattack, city officials said Thursday.

City officials learned there was an outage affecting various internal and customer-facing applications at 5:40 a.m., Chief Operating Officer Richard Cox told reporters. The outage, which included the encryption of some city data, did not affect the public safety department, water department or Hartsfield-Jackson Atlanta International Airport, he said.

But some applications that people use to pay bills or access court information were affected. Cox said the investigation will determine whether any personal information has been compromised.

Mayor Keisha Lance Bottoms urged city employees and the public to monitor their bank accounts and to take proactive steps to protect their personal data.

The city is working with federal agencies, including the FBI and the Department of Homeland Security, as well as private sector partners, to determine the cause of the outage and to fix the problem, Bottoms said. When asked if the city would pay a ransom to resolve the problem, Bottoms said the city would seek guidance from federal authorities on the best course of action.

The attack was discovered by the city’s information security team, which noticed “something that looked peculiar” on the server and began investigating, acting Chief Information Officer Daphne Rackley said.

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