Children flaunting new school gear caught up in shooting in new Sandy Hook Promise campaign video

A powerful video shows children flaunting their new school gear as a shooting begins, forcing them to use the items in life-saving ways.

The Sandy Hook Promise (SHP) - set up after murder of 26 people, including 20 children, at an elementary school in Connecticut in December 2012 - hopes the video will serve as a "public service announcement" and raise awareness of its campaign to spot potential attackers.

In the footage, children happily show off their new bags, folders and headphones as the scene unfolds to the beginning of an attack at a school, prompting the kids to use their accessories in unexpected ways.

"My parents got me this skateboard I wanted, it's pretty cool," one boy says as he smashes a window with his gift.

In one of the more chilling scenes, a tearful young girl texts "I love you mom" while cowering in the corner of a bathroom cubicle before saying to the camera: "I finally got my own phone to stay in touch with my mum."

The video, published on Wednesday, is meant to encourage viewers to "know the signs" and understand "gun violence is preventable".

The charity has put together a guide to help spot the signs before violence erupts.

"SHP’s mission is to create a culture engaged in preventing shootings, violence, and other harmful acts in schools," the organisation states on its website.

"Our words, actions, and impact nationwide are intended to honor all victims of gun violence by turning our tragedy into a moment of transformation."

According to SHP, which produces a video every year to bring attention to its mission, signs to look for are social isolation, threatening behaviour, over-aggression and an obsession with firearms, among others.

Its 2016 video, titled Evan, illustrating how such signs can be overlooked, has been watched more than 11 million times.