UnitedHealth Group says in a memo to workers there's no reason to believe an armed man arrested Monday outside the company's Minnetonka campus had any specific grievances against its UnitedHealthcare business, which is the nation's largest health insurer.

Even so, the message to employees sent late Monday and obtained by the Minnesota Star Tribune directs workers to an employee assistance program as well as internal leaders who can help schedule appointments with licensed counselors, if needed.

"We understand this incident may have impacted you in a number of possible ways, and we want to remind you of our emotional well-being support resources," the company said in the memo.

The incident, which for a time prompted a lockdown inside the company's two-building campus in Minnetonka, has further rattled nerves at a business that was rocked in December by the killing of UnitedHealthcare Chief Executive Brian Thompson on a public sidewalk in New York City.

On Monday, a man was taken into custody after he apparently made threats from his vehicle, which was parked near UnitedHealthcare's headquarters.

The man made a phone call to the FBI, authorities said, and threatened violence toward the facility if his needs were not met. He was apprehended without incident after about an hour, according to police.

A gun was recovered in the front passenger seat of his vehicle, police said.

Law enforcement officials said Monday evening that their early investigation found no indication of specific grievances held by the man against UnitedHealthcare.

In the internal memo, parent company UnitedHealth Group says it responded by activating emergency response protocols for a safe work environment while reinforcing security guidelines and building access policies.

"Based on what we know of the situation, the individual made no demands against UnitedHealthcare," the company said in its message. "There is no reason to believe there were specific grievances against the company.

"As we continue to learn more about the situation near our Minnetonka offices [Monday], the safety and security of our employees remains our top priority. ... We are grateful that law enforcement and our onsite security team acted quickly to resolve the situation."

Eden Prairie-based UnitedHealth Group is one of the nation's largest companies, with about 400,000 workers including 19,000 in Minnesota.