exclave

Azerbaijan demanded that Armenia give part of this region as a "corridor" to its exclave of Nakhchivan.

For Europe, the latent threat to Nato countries comes primarily from Russia's missiles, some of which are stationed on the Baltic coast in Russia's exclave of Kaliningrad.

The route will connect Azerbaijan and its autonomous Nakhchivan exclave, which are separated by Armenian territory.

Its unclear where the vessels are bound for, though all three have continued sailing through the Baltic and may be moving towards ports in mainland Russia or Kaliningrad - an exclave between Poland and Lithuania.

Lithuania - a member of the Nato military alliance - also shares a border with Kaliningrad, a heavily militarised Russian exclave on the Black Sea.