Walmart has joined the list of firearms retailers tightening their rules after a Florida school shooting, saying it would impose a new age restriction on buying guns and ammunition.

“In light of recent events,” the company said, it would require people to be 21 or over to buy guns and ammunition and would pull items “resembling assault-style rifles” from its website, including toy guns.

The line was almost certainly a reference to the bloodshed earlier this month at Marjory Stoneman Douglas High School in Parkland, Florida, where a gunman shot and killed 17 students and teachers.

While past mass shootings have done little to affect gun policies, the response to the Parkland shooting – publicly dominated by student survivors who have championed more stringent gun laws – has begun to produce concrete results.

Dick’s Sporting Goods, another prominent seller of guns, announced earlier in the day that it would stop selling assault-style rifles and high-capacity magazines while imposing a 21-and-over rule for gun purchases.

While Republicans in Washington rejected calls to raise the minimum age for buying guns to 21, Florida’s Republican governor and Republican-controlled legislature have embraced the idea.

Florida shooting – in pictures Show all 10 1 /10 Florida shooting – in pictures Florida shooting – in pictures Police arrest a suspect in connection with the shooting at the Marjory Stoneman Douglas High School in Parkland, Florida Reuters Florida shooting – in pictures Parents wait for news after reports of a shooting at Marjory Stoneman Douglas High School in Parkland, Florida AP Florida shooting – in pictures Anxious family members wait for news of students AP Photo/Wilfredo Lee Florida shooting – in pictures Students being evacuated from the school AP Florida shooting – in pictures Students being evacuated from the school Getty Florida shooting – in pictures People gather waiting for word from students AP Florida shooting – in pictures Parents waiting for news on their children AP Florida shooting – in pictures People gather at a hotel where students were taken after the shooting Getty Florida shooting – in pictures Florida Governor Rick Scott speaks to the media as he visits Marjory Stoneman Douglas High School following the shooting AFP/Getty Florida shooting – in pictures Dr. Igor Nichiporenko, Medical Director Trauma, left, and Dr. Evan Boyer, Medical Director, Emergency Services, speak about treating victims and the suspect at a press conference outside Broward Health North hospital AP

Donald Trump has also backed raising the age for certain gun purchases to 21, and in an extraordinary public break with the National Rifle Association – a powerful political ally – he said he supported an array of other gun control measures during a televised meeting.

Donald Trump says the NRA 'have less power over me' during school safety discussion