Drug gangsters in northern Mexico looking for high-powered weapons have benefited from some well-placed American suppliers lately, U.S. prosecutors say.

While drug violence raged in the Mexican town of Puerto Palomas, the mayor and police chief of next-door Columbus, N.M., formed part of a U.S. smuggling ring selling weapons to gangsters across the border, U.S. prosecutors say.

Columbus Mayor Eddie Espinoza, Police Chief Angelo Vega and nine others amassed weapons beginning in January 2010 for sale across the border, according to an indictment unsealed Thursday. At least a dozen of the 200 guns they purchased later turned up in Mexico.

The suspects were arrested Thursday in a raid by federal agents and state police. One suspect is at large.

Court records show that many of the weapons, including 9mm handguns and AK-47-style pistols that resemble a shortened version of the rifle, were purchased at Chaparral Guns, a federally licensed arms dealer, and sold in bulk purchases of up to 20 at a time. The store's owner, Ian Garland, was taken into custody and charged with smuggling, making false statements and conspiracy.

Residents of Columbus say news of the sweep hit the town hard, coming two days before an annual heritage celebration in honor of friendship and peace between Puerto Palomas and Columbus, which was famously attacked in 1916 by Mexican rebel leader Francisco “Pancho” Villa.

“I’m so mad I could spit nails,” said Martha Skinner, who runs a bed and breakfast in Columbus, a town of about 1,800. “They took an oath to uphold the law. What if the cartels decided they weren’t selling enough guns and got mad and sent someone to shoot up our town?”

Federal prosecutors have filed 84 counts against the defendants, who allegedly engaged in the kind of “straw” purchases that have drawn increasing scrutiny from U.S. authorities, wherein gun buyers legally acquire weapons, often in large quantities, on behalf of criminals.

Trafficking of U.S. guns into Mexico, where firearms are strictly controlled, has been a source of increasing tension between the two countries, and Mexican officials have pressed the Obama administration to do more to stem the flow of weapons south.

Like nearby El Paso and Ciudad Juarez, Columbus and Puerto Palomas have experienced Mexico’s drug violence in dramatically uneven ways. Columbus residents say their town has remained quiet, unfazed by the murders on the other side or such events as the discovery of 20 bodies in a mass grave in November.

When three human heads were left in the town square of Puerto Palomas in August, Vega, the police chief, told reporters that the violence was “knocking at our back door.”

“We’ll maintain the line,” he said at the time.