Officials in Vilnius, the capital of Lithuania, have unveiled an evacuation plan that would be used in the event of an invasion of the city.
It sets out how the city's 540,000 residents would be ordered to leave if it were close to being overrun by enemy forces.
The plan's publication comes amid heightened fears over Russia's military ambitions in the region, in light of the ongoing full-scale invasion of Ukraine.
Lithuania, along with fellow Baltic states Estonia and Latvia, has long warned about the threat of Russian aggression and has heavily invested in defence in recent years.
Vilnius is located close to the 679-km (422 mile) border which Lithuania shares with Belarus, a staunch Russian ally.
Belarus hosts thousands of Russian troops and was used as a springboard for the failed February 2022 attempt to capture the Ukrainian capital Kyiv.
Lithuania – a member of the Nato military alliance – also shares a border with Kaliningrad, a heavily militarised Russian exclave on the Baltic Sea.
The evacuation plan unveiled on Wednesday identifies 150 routes out of Vilnius and assigns neighbourhoods with specific evacuation points, Lithuanian public broadcaster LRT reported.
Residents would be told to evacuate via SMS and siren warnings, with a dedicated app communication system also under development.
The plan calls for some roads and a bridge to be expanded in order to allow the safe and rapid flow of people out of the city.
Vilnius Mayor Valdas Benkunskas stressed that any evacuation would be a last resort should a military defence of the city fail.
He said the publication of the plan should not cause "panic" and stressed it did not imply an increased threat.
The plan incorporates elements of how Ukraine responded to Russia's invasion, especially the ways in which Kyiv endured the early days of full-scale invasion.
Officials said the Vilnius plan was primarily developed with an invasion in mind but said it could also be deployed in the event of a natural disaster, nuclear attack or a major collapse of essential infrastructure.
Lithuania was formerly part of the Soviet Union and declared its independence in 1990, after which it sought closer ties with Western Europe, including joining the European Union.
It has been a vocal supporter of Ukraine and, like its Baltic neighbours, has repeatedly warned of the threat the Kremlin's expansionist ambitions could pose to the region.
Belarus and Russia are due to hold joint large-scale military drills in September, which could potentially see troops stationed close to Lithuania's border.
Military strategists have long considered the so-called Suwałki gap – a narrow stretch along Lithuania's border, which runs between Kaliningrad and Belarus – a potential vulnerability in Nato's defences
Its occupation would cut off land routes linking Poland to Lithuania, and onto the rest of the Baltic countries.
