US parents beef up child security following mass shootings.

With the back-to-school season underway, Australia is fortunate not to follow one trend emanating from the US.

CNN reports that sales of bullet-proof backpacks for children have surged following a spate of school shootings across the country.

Instead of letting their children choose a plastic backpack covered in Hello Kitty or Spider-Man, some parents are purchasing bags that double as shields in case kids get caught in gunfire.

Companies such as Guard Dog Security, Bullet Blocker and TuffyPacks designed bulletproof backpacks to quell parental concerns.

The retailers said backpack sales spike during the back-to-school season, and all three said they they saw a significant uptick in the aftermath of mass shootings.

Joe Curran founded Bullet Blocker 12 years ago after a shooting at Virginia Tech killed 33 people.

To protect his two school-aged children, the former sheriff's deputy inserted body armor into their backpacks, he said. Classmates' parents asked for inserts for their children's bags, and it grew into a business.

Sales have increased 200 per cent since the recent mass shootings, Curran said.