LAKELAND, Fla. — If you're carrying a gun, the Publix supermarket chain doesn't want to see it.

Publix is joining a growing number of retailers in asking customers not to openly carry firearms in its stores, even if state laws allow it.

The new policy comes a week after the competing Kroger grocery chain joined Walmart, Target , and other companies in asking customers not to openly carry weapons in their stores. The policies don't amount to outright prohibitions, in particular because stores generally haven't said how their workers should deal with customers who don't voluntarily follow the rules.

Private companies are increasingly stepping into the national gun debate following recent mass shootings at a Walmart in El Paso, Texas and Dayton, Ohio.

Publix made its announcement the same day CEOs of more than 100 companies, including Airbnb, Twitter and Uber, sent a joint public letter to the Senate asking for expanded background checks for gun purchases and a strong federal "red flag" law.

Publix's policy change was more discreet. Sent by email on Wednesday, the one-sentence statement said: "Publix respectfully requests that only law enforcement officials openly carry firearms in our stores." Publix made no immediate announcement on its Twitter and Facebook pages, and did not respond to multiple requests for comment seeking clarification on the new directive.

The chain based in Lakeland, Florida, has 1,226 stores in Florida, Georgia, Alabama, South Carolina, North Carolina, Tennessee and Virginia.

Civilians generally aren't allowed to openly carry guns in Publix's home state of Florida, which joins other states in the South in allowing residents to carry concealed weapons with a permit.

However, Alabama, North Carolina and Virginia allow guns to be carried openly, though some municipalities of Virginia do not allow it. Georgia allows open carry only with a permit, as does Tennessee, but Tennessee recently gave businesses the right to fully ban openly carried guns on their premises.

North Carolina also allows businesses to ban open carry. South Carolina allows only long guns to be carried openly.

Survivors of last year's massacre at Marjory Stoneman Douglas High School have criticized Publix for donating to a Florida gubernatorial candidate aligned with the National Rifle Association.