WASHINGTON, March 2 (Xinhua) -- A few U.S. retailers, including the world's largest, Walmart, announced they would raise the minimum age required to buy firearms and ammunition to 21 from 18 following the tragic shooting in the state of Florida that claimed 17 lives.

Walmart announced on Wednesday that it's a decision made "in light of recent events." Earlier in the day, Dick's Sporting Goods announced a similar policy change on the minimum age to purchase a gun. Grocery store chain Kroger told CNBC on Thursday that its Fred Meyer stores will also adopt such measures.

The announcements were met with mixed reactions on social media. Many are clamoring it's still not enough. A netizen, @purva_arts, tweeted: "That's still crazy though how easily people have access to firearms in America!" Another netizen, @ReRodela, tweeted: "What kind of world do we live in when Wal-Mart and a store called Dicks are the good guys lol."

Last week, U.S. President Donald Trump indicated he was open to raising the minimum age to buy some kinds of guns and tightening background checks, as the Florida school shooting prompted a public outcry for action.

"I will be strongly pushing Comprehensive Background Checks with an emphasis on Mental Health. Raise age to 21 and end sale of Bump Stocks," Trump said in a series of tweets.

A 19-year-old gunman killed 17 people on Feb. 14 by firing an AR-15 style assault rifle in a high school in Florida. Officials said the suspect purchased a gun legally at Dick's in November, but the AR-15 used in the shooting was bought at another store.

In its announcement, Dick's also said it would stop selling assault rifles and high-capacity magazines. Walmart, which had stopped selling assault rifles in 2015, said it would now also remove online items that resemble such weapons.