Gov. Tim Walz activated the Minnesota National Guard on Tuesday to assist St. Paul in responding to a cyberattack on the capital city.

The governor's office said "the magnitude and complexity of the cybersecurity incident have exceeded the city's response capacity." The guard will provide cyber protection support to the city immediately.

"We are committed to working alongside the City of Saint Paul to restore cybersecurity as quickly as possible," Walz said. "The Minnesota National Guard's cyber forces will collaborate with city, state, and federal officials to resolve the situation and mitigate lasting impacts. Above all, we are committed to protecting the safety and security of the people of Saint Paul."

Mayor Melvin Carter said the city first detected "suspicious activity" on Friday morning, triggering an "immediate and coordinated response."

"We now know that this was not a system glitch or technical error, this was a deliberate, coordinated digital attack carried out by a sophisticated, external actor intentionally and criminally targeting our city's information infrastructure," Carter said.

In addition to city staff and the National Guard, the FBI and two national cybersecurity firms are working to investigate the attack.

In a statement to WCCO, the FBI said it is "working with partners and lending our investigative expertise," and declined to comment further.

Carter also declared a state of emergency, which authorizes the city's departments of Emergency Management and Office of Technology and Communications to deploy local, state and federal partners to help with the response.

While the threat is "dynamic and ongoing," Carter said, there's "not necessarily an acute threat to a resident at home somewhere." So far, only city systems have been affected, such as Wi-Fi in city buildings and network access for internal applications. As a result, some workers are unable to do their jobs.

Carter says the biggest impact to residents is paying city bills online. Internet services at libraries and some recreation services are also down.  

"We are the victims of a serious crime," St. Paul's Chief Information Officer Jaime Wascalus said. "We will not restore services until we have complete confidence in our understanding of the incident."

Earlier, the city said it was experiencing "unplanned technical disruptions" and some services may be delayed or unavailable as a result.

St. Paul said 911 was still available for emergencies.

Local cybersecurity expert Craig Sixta said in most cases, the hackers are seeking a ransom. He says these kinds of attacks can be difficult to beat, with the attacker likely able to gain access through just one city worker clicking on a phishing email.

A similar disruption impacted Ohio's largest last year, but no personal information was taken.

• St. Paul