Eyewitnesses of terrorist attack are being forewarned to flee the vistum rather than to continue efforts to movie or picture inhumanities on their phones.
The informing is part of a police safarus pushing for children in academies to be taught what to do in the event of a terror attack.
Police directors say provide advice in classrooms could save lives.
The campaign follows a number of assaults in the UK this year, including a bombing at a Manchester pop concert.
An attack earlier this month on a London Underground train in Parsons Green encountered idols of a partially-exploded device posted online within minutes.