Authorities have arrested a former Minneapolis public works employee on suspicion that he threatened to harm city employees after losing his job earlier this year, sources said.

The man, whose identity hasn’t been released, was arrested Friday on a warrant from Ramsey County, according to a police spokesman.

Spokesman John Elder said that the case prompted the department to re-evaluate its security measures, as it would with any threat.

“It’s commonplace that the Minneapolis Police Department evaluates any sort of threats of potential concerns and will address staffing to meet those,” Elder said. He referred further questions to the Ramsey County Attorney’s Office, which is prosecuting the case.

A search of jail records in Ramsey and Hennepin counties did not turn up any inmates being held on charges involving threats.

Police began investigating the man after he checked himself in to St. Paul’s Regions Hospital, where he told staff that he had hidden a bag of guns near a water-treatment facility in Minneapolis, said multiple sources familiar with the investigation. The man told hospital staff that he intended to harm Minneapolis city employees, putting City Hall on high alert.

According to the sources, Minneapolis police officers searched the area around the facility where the firearms were reportedly stashed but found no weapons. In the meantime, the man was released from Regions, only to have a warrant issued for his arrest, according to the sources.

So far, little is known about the suspect, other than he was still in his probationary period with Public Works, the city’s largest department, when he was terminated for reasons that aren’t entirely clear.

The case was later referred to Ramsey County prosecutors for possible charges because even though the alleged threats were directed at a location across the river, they were made while the man was in St. Paul, according to Chuck Laszewski, a spokesman for the Hennepin County Attorney’s Office.

“It all happened over in St. Paul, so we don’t have jurisdiction over it,” Laszewski said.

The episode set off alarm bells at City Hall, where officials spent the week quietly informing department heads about developments in the case.

In an e-mail sent Tuesday, outgoing City Coordinator Nuria Rivera-Vandermyde wrote that the city would offer active-shooter response training sessions for its employees.

“We are in the midst of planning active-shooter readiness trainings, and given the rise of workplace violence and tragedies like the events over the weekend, we have asked that Property Services work to make these trainings available to all departments and facilities across the enterprise in the coming months,” she wrote, referring to a mass shooting in West Texas over the Labor Day weekend in which a lone gunman killed seven people and wounded 25. “While we cannot control for every eventuality, we want to make sure we take as many steps as we can to increase security and provide you all with situational awareness tools that could keep you safe.”

The trainings have been talked about since June, when City Council Vice President Andrea Jenkins expressed concerns about lax security at City Hall.