A doctor from Oklahoma, inspired by one of America’s deadliest school shootings, has invented an unusual defense against crazed gunmen who open fire in classrooms: a bullet-proof blanket.

Steve Walker, a 43-year-old father of two, said he developed the orange-colored shield - compared by US broadcaster NPR to a yoga mat - to give children greater protection from shootings and tornadoes. Walker says he was left frustrated by the murder of 20 children and six adults at Sandy Hook Elementary School in December 2012 and by a deadly tornado that hit schools in Oklahoma in May 2013. A gunman and a student were killed at an Oregon high school on Tuesday in the latest attack. Everytown for Gun Safety, the group set up by billionaire former New York mayor Michael Bloomberg to end gun violence, says there have been 74 school shootings since Sandy Hook.

The massacre triggered intense debate about relatively lax US gun control laws, but measures supported by President Barack Obama failed in the Senate due to fierce opposition from gun rights supporters led by the National Rifle Association.

Walker said he and his co-inventors wanted to get above the political deadlock and ‘develop something that hopefully both sides can agree upon.’

‘We really don’t take one side or another, because doing that just gets you where we currently are, and that is no protection for our children,’ he said by telephone from Oklahoma.