Walgreens Boots Alliance Inc. and Kroger Co. will stop selling electronic cigarettes, making them the latest retailers to take action in the wake of the outbreak of vaping-related lung injuries.

“We have made the decision to stop selling e-cigarette products at our stores nationwide” as federal health officials continue to study the issue, a Walgreens spokesman said in an email Monday. The drugstore chain, which operates thousands of locations around the U.S., will still sell regular cigarettes.

Kroger said earlier that it too would halt the sale of all electronic nicotine-delivery products, citing mounting health questions. The moves by Walgreens and Kroger follow a similar decision by retail giant Walmart Inc. last month.

More than 1,000 people have suffered lung injuries from vaping devices this year and 18 people have died, according to the latest tally by the U.S. Centers for Disease Control and Prevention.