Wegmans requested that customers refrain from openly carrying firearms. (Representational)

US pharmacies CVS and Walgreens and supermarket chain Wegmans on Thursday asked customers not to openly carry firearms in their stores, or not to bring them in at all.

The calls by the stores -- which follows a similar move by Kroger, the country's biggest supermarket chain -- come as the United States grapples with an epidemic of gun violence and frequent mass shootings.

CVS said on Twitter that it supports "the efforts of individuals and groups working to prevent gun violence," and requested that customers who are not law enforcement personnel refrain from bringing firearms into its stores.

Walgreens meanwhile only asked that customers not openly carry guns, providing no explanation for its decision in a brief statement on its website.

Wegmans also requested that customers refrain from openly carrying firearms, tweeting: "The sight of someone with a gun can be alarming, and we don't want anyone to feel that way at Wegmans."

Retail giant Walmart announced on Tuesday that it would halt the sale of ammunition for handguns and some military-style rifles, calling the status quo on firearms in the United States "unacceptable."

That announcement came a month after a deadly shooting at one of the chain's stores in El Paso, Texas, that claimed 22 lives.