MAYFLOWER, Ark.—Auctioneers preparing for an estate sale Saturday morning made an explosive discovery among the china and other items up for bid — a suitcase full of military-grade explosives.

The rusted, padlocked suitcase sat alongside a porcelain coffee service set, decorative enamel-finished eggs, a vintage gas-powered model of the 1965 Chaparral II race car prototype and other goods at the backyard sale.

Auctioneers finally opened the suitcase just before the sale and found three blocks of military-grade C-4 plastic explosive, two tubes of a similar plastic explosive, a blasting cap and some dynamite.

Workers quickly called 911 and the Conway Fire Department’s bomb squad collected the materials. The bomb squad put the aging explosives inside a special container and drove them out to an isolated spot to destroy them, district chief Jon McMahon told the Log Cabin Democrat newspaper.

The auction went on as planned.

Faulkner County sheriff’s office Maj. Andy Shock said the explosives had deteriorated over time and likely were at least 15 years old. Shock said that age put the C-4 at the outer limits of its shelf life if it had been stored under dry, ideal conditions. The major said the explosives likely weren’t.

Shock said some of the items at the estate sale belonged to a U.S. Navy veteran who recently died. He said deputies continued to investigate the incident, but charges weren’t likely as the presumed owner of the explosives is dead. But just in case there was any doubt, Faulkner County Sheriff Karl Byrd made sure to stress that owning dynamite or plastic explosives without permission is “definitely illegal.”