The city of Wyoming, Minn., is suing six makers of wet wipes, arguing that so-called "flushable" wipes are clogging plumbing networks and costing the city big money.

The lawsuit, filed Thursday in federal court, might be the first seeking class-action status on behalf of cities grappling with the disposable cloths that wastewater officials say are plugging pipes and pumps.

"These flushable wipes do not degrade after flushing," the city of Wyoming's suit says. "Rather, the flushable wipes remain intact long enough to pass through private wastewater drain pipes into the municipal sewer line, causing clogs and other issues for municipal and county sewer systems and wastewater treatment plants, resulting in thousands, if not millions, of dollars of damages."

But representatives of the industry behind wet wipes argue that people are flushing cloths that never claimed to be flushable, such as cheap baby wipes, meant to be bundled in disposable diapers and thrown in the trash.

That industry has "empathy for the challenges the wastewater operators are having with nonflushable materials impacting their systems," said Dave Rousse, president of the Association of Nonwoven Fabrics Industry, a trade group representing manufacturers of wipes and other products. "However, we take great exception to any effort to blame flushable wipes for the problems being caused by nonflushable wipes."

Makers of wipes — including baby, facial and cleaning wipes — have faced increased criticism as their industry has grown. In 2014, a New York man sued Kimberly-Clark Corp. and Costco Wholesale Corp. in federal court with a class-action-styled complaint that featured "homeowner horror stories" of "flushable" wipes clogging homes' plumbing.

But until now, cities have not brought forward such a suit, said Garrett Blanchfield, a partner at Reinhardt Wendorf & Blanchfield in Minneapolis, representing Wyoming, population 7,800.

In its lawsuit, Wyoming is seeking "a declaration that the defendants' flushable wipes do not degrade and are not sewer safe," an order that the companies stop advertising them as such, and the establishment of a fund to compensate cities for the costs of cleaning and removing wipes from their sewer systems.

"They want to make sure that people know that these things really aren't flushable," Blanchfield said.

A spokesman for Kimberly-Clark, one of the companies named in Wyoming's suit, declined to comment on the litigation. But the company does "extensive testing" on the wipes it calls "flushable," said Bob Brand, director of external communications for the Texas-based company. They include Kleenex Cottonelle FreshCare, which it labels with the words "SafeFlush Technology," beside an image of a wipe going down a toilet.

"Our wipes do break down," Brand said.

Across Minnesota and the country, cities have been cautioning residents not to flush wipes, which have forced them to boost their monitoring and buy expensive grinders. Wadena, Minn., posted its warning on Facebook: A wipe labeled flushable "only means they will fit down the piping within your home."

But down the line, wipes can catch on joints and tree roots, cities say. They wind around pumps at lift stations, which bring wastewater to higher elevations, get caught in screens and form massive clumps so common that they earned a nickname: polar bears.

Linda White, who has a house in Wadena County, was struck by Wadena's warning.

"I think people really do need to be educated on why they should not be flushing them into the septic systems," she said. "I was shocked at how expensive it was to the city of Wadena to take care of this problem."