South Yorkshire Police has issued advice to anyone travelling abroad over the summer holidays.
Officers have told people to check the latest Foreign Office travel advice, to sort out travel insurance and watch the force's safety video.
The force said: "The chances of being caught up in a terrorist incident are still low but sadly we have seen atrocities take place in the UK and abroad.
"So it is important everyone stays alert and knows what to do if the worst was to happen.
"We want people to think of this in the same way they do the safety film airlines show before take-off.
"They don’t expect anything bad to happen, but it is a sensible safety precaution to show people what to do."
The key advice is:
Run – to a place of safety. This is better than trying to surrender or negotiate.
Hide – it is better to hide than confront. Barricade yourself in, turn your phone to silent and use only when it is safe to do so.
Tell – Make sure you know the local emergency numbers in the country you’re travelling to. For all EU countries it is 112.