Correspondent Dan Rivers joins Ukraine's patrols in the Sea of Azov, which separates Ukraine from Russia. This week, Russia sent six landing ships to the Black Sea.
As the world contemplates a possible Russian invasion of Ukraine, in Mariupol they’ve been living in the shadow of this threat for eight years. The industrial port city of half a million people has steel at its heart.
Two massive Soviet-era factories churn out the metal along with clouds of steam and smoke, dominating the skyline and the economy here. But it is the simmering conflict a few miles to the east, between the Ukrainian army and Russian-backed separatists, which occupies the minds of its residents.
Ceasefire violations are a daily occurrence. In practice that means drone attacks, sniper fire and low level provocations mostly from separatist side which ensure there is an edge to this frontline city. We travelled out to one tiny village of Pavlopil a couple of miles from the trenches.
Anatoly Kondratenko, 62, shows me where a drone dropped a grenade on his house, shattering a window. He was very lucky it wasn’t worse. This is the third time Mr Kondratenko's modest single-storey home has been targeted, but he tells me that despite the risks he doesn’t want to leave. He’s lived in this village since 1966. He explains how he has his dogs, his garden, his vegetable patch and doesn’t see why he should give them up.
The odd attempt to bomb him is accepted with a world-weary shrug. It’s just part of life in this part of the Donbas. Despite the shadow of fighting nearby, Mariupol is actually a thriving city. Trendy bars and restaurants have sprung up in recent years, which wouldn’t be out of place in the hippest neighbourhoods of London or New York. The economy has been buoyed by migration from the separatist held areas, into the city, where young people feel freer to live without the restrictions prevalent in the Donetsk People’s Republic.
The city faces the Sea of Azov bordered by Russia and enclosed by the Crimean peninsula, which it annexed. Russia has recently sent four landing craft from the Baltic to the Black Sea, amid fears that if a full scale invasion were to happen, a seaborne assault may form part of a Russian strategy to seize a swathe of coast from the Crimea to Mariupol. If that were to happen, it would place the Sea of Azov firmly under Russian control.
For the men and women of Ukraine’s maritime border force it means extra vigilance is now needed during their patrols. They encounter Russian vessels most days, which constantly probe their abilities. We accompanied them for a short sprint across the water in their 1200 Horsepower patrol boat, capable of 45 knots.
But despite their agility, Ukrainian’s maritime assets would be no match for the might of the Russian Navy. The boat we were on isn’t armed; instead it monitors Russian movements, policing a narrow strip of strategically important sea. The captain describes the typical encounters with their Russian adversaries, who often approach at high speed in aggressive manoeuvres.
The recent flurry of diplomatic activity may have given hope that this crisis can be defused without blood being spilt, but on the sea of Azov the Ukrainians are not dropping their guard.