A Russian Mi-8 helicopter crossed 1,000 feet into Nato airspace this week, prompting warnings to residents about preparedness.
The helicopter came from the heavily militarised Kaliningrad region close to the Polish town of Braniewo.
It flew above Polish territory for around 42 seconds, triggering Nato fighter jets to scramble in response.
Poland saw the move as a deliberate transgression to test Nato defences, but also a sobering warning to residents to be prepared in case of a needed evacuation.
The country’s deputy prime minister and foreign minister Radosław Sikorski revealed he had an evacuation backpack ready amid fears of full-scale war.
Sign up for all of the latest stories
Start your day informed with Metro's newsletter or get alerts the moment it happens.
Oxford-educated Sikorski, 63, told Fakt newspaper it was better to be ready for war amid intelligence reports that Putin could strike a Western state this year.
‘I have stocks of rice, I have a hand pump at home, and I have also made preserves from fruit from my own garden,’ he said.
‘I have the safety instructions, and I have also thought through where the nearest place of shelter is. Everyone should also know how to apply a dressing. That is useful even in peacetime.’
Asked whether people should prepare a bag with emergency provisions, he said: ‘We have all received the safety instructions, and if the state tells a citizen, ‘Listen, these are unsettled times, it is better to be prepared’, it does no harm to listen to that.
‘That is my appeal — to listen to it.’
The Polish Armed Forces released a statement about the helicopter incursion, reading: ‘The aircraft’s flight was tracked by the radar systems of the Polish Armed Forces.
‘Fighter jets were scrambled, and ground-based forces and assets remained on alert. The nature of the incident indicates that Russia is once again testing the readiness of our air defence.
‘Polish air defence crews are conducting round-the-clock surveillance, remaining in a state of constant readiness to ensure the security of Polish airspace.’
In March this year, the EU told its almost 450million citizens to prepare for war or natural disaster by assembling ’72 hour survival kits’.
Get in touch with our news team by emailing us at webnews@metro.co.uk.
MORE: Why Andy Burnham has been talking about Russia this week
MORE: Man jailed for writing ‘Putin is a d***head’ on ballot paper
MORE: Putin and his mate joke about who is the biggest dictator