Some Minnesotans may be loosening their own rules about when to wear a mask, if at all, to help stem the spread of COVID-19. But retailers are staying firm with theirs, and some municipalities are joining them.

At the Menards in Maplewood, a large sign secured to a tarp informs customers that masks are required to shop at the home improvement store.

Like Target and most grocery stores, all employees are required to wear masks. And like Costco, Menards also mandates masks for customers in most of its locations, including the Twin Cities.

"We are simply unable to provide service to anyone who doesn't wear a mask," said Jeff Abbott, spokesman for Menard Inc., which is based in Eau Claire, Wis.

As the state loosens restrictions on activities where people will interact with others — for example, bars can now be open and youth outdoor sports are allowed — municipalities such as Edina are joining Minneapolis and St. Paul in requiring masks in indoor areas.

The University of Minnesota also now is requiring masks in enclosed indoor spaces.

But while retailers and some cities are firm on the need for masks, enforcement is a challenge. Government and business leaders have said they hoped public awareness campaigns and clear signage could help educate people, especially after several well-publicized violent attacks by customers without masks when they were confronted.

Target requires masks of customers only in cities that mandate it. The Minneapolis-based retailer, though, strongly encourages that everyone wear masks and social distance in the stores.

In a municipality that requires masks, employees will remind customers as they enter stores about the regulation. It relies on local officials to enforce the mandate, though, said Target spokesman Joshua Thomas.

"Safety of both team members and guests is going to always be our number one priority," Thomas said.

In the Los Angeles area, a Target employee in May broke his arm as two men who refused to wear masks were being escorted out of the store, according to news accounts.

Also in May, a Menards employee in Mankato was allegedly slapped after asking a customer to comply with the mask rule, according to the Mankato Free Press.

Other confrontations were more violent. In Flint, Mich., a security guard at a Family Dollar store was shot and killed when he asked a relative of those arrested to leave because she wasn't wearing a mask.

Making sure customers wear masks is yet one more challenging task for local small businesses, many of which are just reopening and also dealing with best practices for cleaning and social distancing.

Jill Pavlak, co-owner of Urban Growler Brewing Co. in St. Paul, said she wants masks mandated metro­wide not only for indoor areas but also for when people are ordering and picking up food and beer outside.

"I don't like having to police people to wear a mask. … I just want to run a brewery," she said. "I don't want to have to explain to every person why we have the policy."

Most customers the brewery hosts on its outdoor patio area comply and wear masks until they are seated at their spaced-out tables. However, 10% of people get annoyed or angry about the policy, Pavlak said.

Many retailers are hesitant to have employees physically enforce the rules, relying on signage and other education messages, retail experts say.

"It's very common in retail to instruct employees not to try to stop or chase shoplifters in order to avoid an unnecessary risk of violence, and many retailers have applied the same theory to masks," said Craig Shearman, a spokesman for the National Retail Federation, in an e-mail. "Given the incidents of violence we have seen when some customers object to wearing masks, retailers do not want to let disagreements escalate to the point of confrontations."

Nationwide, the debate on wearing masks in stores is increasingly polarized — and politicized. Store employees are oftentimes the ones in the middle, said Kim Sovell, an adjunct professor of marketing at the University of St. Thomas who focuses on omnichannel retailing.

"The issue with retail employees is their job has become to enforce this rule," she said. "I think that's a tremendous amount to ask someone who has been working for $15 an hour."

Sovell, who also has taught on consumer behavior, believes more people will be influenced to wear masks if they see others wearing them. "We really do want to fit in," she said, recounting a story from an acquaintance who said if he wore a mask in a certain store people would laugh at him.

While Minnesota has seen fluctuating trends in confirmed case counts recently, cases are rising quickly in states like California, Texas, Florida and Arizona. Infectious disease expert Dr. Anthony Fauci told senators Tuesday that new cases could rise to 100,000 a day.

On Tuesday, the Minnesota Department of Health reported that 36,303 Minnesotans have had lab-confirmed cases of COVID-19, an increase of 444 from the day before. Six deaths recorded Tuesday bought the state's death toll to 1,441, including two residents of group-living facilities.

Lynn Bronson of St. Paul said in an e-mail that she wears her mask whenever she goes somewhere where she will be indoors or fewer than 6 feet away from people.

"I want my kids to be able to go back to school this fall, and I want my elderly parents to be able to leave their home again," Bronson said. "I wear a mask to be part of the solution, not the problem, and I believe we owe it to our community to do everything we can to lessen the effects of this pandemic."

Staff writer Joe Carlson contributed to this report.