The image above is that of a leaflet which - as part of Counter Terrorism Awareness Week - was distributed yesterday by the police at railway stations around the UK to guard people against a possible Mumbai-style attack that security forces are expecting may be attempted by Muslim extremists.
The leaflets tell the public to "run, hide and tell" in the event of such an attack.
They are part of a campaign just launched by Chief Constable of British Transport Police (BTP) Paul Crowther, who said: "More than six million people travel on our railways every single day."
He added: "Earlier this month a man was sentenced for terrorism offences after being caught in possession of information about how to make bombs.
"This was as a direct result of a rail passenger reporting suspicions to train staff. We need others to follow suit and play their part in keeping the UK's transport systems safe from terrorists."
The government has warned that the threat to Britain from Islamic radicals is "greater than ever".
Home Secretary Theresa May has just published a Counter-terrorism and Security Bill containing a range of new powers, including a legal requirement by schools, prisons and councils to put in place policies to stop would-be extremists being radicalised.
The bill, about to go before Parliament, includes a vast package of measures to tackle the threat from Muslim militants and those returning from fighting with the Islamic State.
It seems to me that much more useful than warning potential victims would be to target the would-be criminals. We know that the Muslim community in Britain harbours many terrorists, some of whom have gone to Iraq and Syria to join the ranks of the beheaders and torturers of the Islamic State and have been let back into the UK.
These home-grown jihadists have done us a favour, first by betraying where their loyalties lie and second by leaving the country. We should use both favourable conditions and not allow them to return to Britain, making them stateless if necessary.
British security services have informed that since the 2005 7/7 attacks in London, that killed 52 people, no fewer than 40 terrorist plots have been disrupted in the UK.
Home Secretary Theresa May disclosed this week: "There have been attempts to conduct marauding 'Mumbai-style' gun attacks on our streets, blow up the London Stock Exchange, bring down airliners, assassinate a British ambassador and murder serving members of our armed forces."
In the 2008 attacks in Mumbai, India, which security chiefs believe are inspiring the current Muslim militants, a group of Pakistani men linked to the terror group Lashkar-e-Tayyiba went to various crowded public places across the city - including a railway station, a packed restaurant, two hotels, a cinema and a hospital - armed with machine guns and bombs, slaughtering 164 people.
The attacks only ended when commandos stormed the buildings, killed the terrorists and rescued hostages. The one survivor was later executed.