Eyewitnesses of terror attacks are being warned to flee the scene rather than try to film or photograph atrocities on their phones.
The warning is part of a police campaign pushing for children in schools to be taught what to do in the event of a terror attack.
Police chiefs say giving advice in classrooms could save lives.
The campaign follows a number of attacks in the UK this year, including a bombing at a Manchester pop concert.
— Terrorism Police UK (@TerrorismPolice) September 28, 2017