Walmart on Tuesday announced it will reduce its gun and ammunition sales and ask shoppers to stop openly carrying firearms in stores after two “horrific” shootings over the summer. In a memo to employees, Walmart CEO Doug McMillon said the company’s changes were prompted by several mass shootings, including ones in stores in El Paso, Texas, and in Southaven, Mississippi.

“We know these decisions will inconvenience some of our customers, and we hope they will understand,” McMillon said. “As a company, we experienced two horrific events in one week, and we will never be the same.”

The mega-store will stop selling ammunition for handguns and some types of rifles, and are requesting customers no longer openly carry firearms, unless they are authorized law enforcement officers, McMillon said. The store will also stop selling handguns in Alaska, the only state where it still sells the firearm. McMillon, however, said Walmart will continue selling long-barrel deer rifles and shot guns, as well as ammunition for hunting and sports shooting. The store will also continue to allow concealed carry by customers with permits in its stores, he said.