Five firearm instructors in the Minneapolis area said sign-ups for safety training, which is required for permit holders, have grown in the past two weeks.

At the Stock & Barrel Gun Club’s two locations near Minneapolis, the classes for people seeking a permit to carry a firearm almost always draw large crowds.

“It’s usually in the hundreds,” David Taylor, the club’s CEO, said.

But since immigration enforcement agents flooded the city, sparking clashes in the streets and the killing of two protesters, interest in the classes has only grown. In just the past two weeks, Taylor said, his club has received four times the usual number of sign-ups.

That does not appear to be an anomaly. Five firearm instructors in the Minneapolis area told NBC News they have seen a similar trend. The sudden interest, they say, is a reflection of the fear and uneasiness that has gripped the region amid the ongoing turmoil in the streets.