A principal in Alabama is asking students to bring cans of food to throw at would-be intruders.

A US high school has asked parents to arm their children with cans of food as part of its response plan against gun-armed intruders.

School officials from W.F. Burns Middle School in Valley, Alabama, wrote a letter to students’ parents, asking them to buy their children “an 8 oz canned food item (corn, beans, peas etc.) to use in case an intruder enters the classroom”.

“We hope the canned food items will never be used or needed, but it is best to be prepared.”

The strategy was inspired by the ALICE Training Institute, a company founded by a former police officer and a former primary school principal.

The institute follows the mantra of: Alert, Lockdown, Inform, Counter and Evacuate, and the cans of food are only a small — but still important — part of the whole procedure, school officials wrote.

“We realise at first this may seem odd; however, it is a practice that would catch an intruder off-guard,” the letter read.

“The canned food item could stun the intruder or even knock him out until the police arrive. The canned food item will give the students a sense of empowerment to protect themselves and will make them feel secure in case an intruder enters the classroom.”

Since the letter was sent out, it has been shared thousands of times, with some questioning its effectiveness.

But Chambers County School Superintendent Kelli Moore Hodge told CNN via email that the point of the training “is to be able to get kids evacuated and not be sitting ducks hiding under desks”.

Since the year 2000, the US has suffered through more than 100 school shootings, including the horrific 2012 Sandy Hook massacre, which claimed the lives of 27 people, 18 of them children.

The letter comes as some states, such as Washington D.C, finalise changes to its concealed gun laws by restricting areas where permit owners can carry guns, such as places of worship.

But new Washington DC mayor Muriel Browster has come out blazing against guns, telling the Washington Interfaith Network that they “have a mayor who hates guns,”

“If it was up to me, we wouldn’t have any handguns in the District of Columbia. I swear to protect the Constitution and what the courts say, but I will do it in the most restrictive way as possible,” the Washington Post reported.

The ALICE training program, whose mission statement reads: “To improve chances of survival”, advocates that even when barricaded in a room, students should still take steps to save themselves, such as hiding and grabbing items with which to defend themselves against the assailant.

The creators of ALICE say more than 1500 schools use their plan.