Ukrainians are on high alert after a confrontation between Ukrainian and Russian ships last weekend in the Kerch Strait – a narrow strip that links the Azov and Black seas.

Russia fired on and seized three Ukrainian ships on November 25. Kiev and its Western allies are demanding that Moscow release the vessels and their sailors.

As reported by the Agence France-Presse (AFP), if the long-running conflict between Ukraine and Russia were to intensify, Ukraine’s industrial port city of Mariupol would likely find itself on the frontline.

Mariupol is only around 10km from the frontline that separates government-controlled territory from Moscow-backed rebel republics.

This is why people are digging ditches in Chervone, a village just south of Mariupol. They say it’s a bid to protect the city from a Russian advance.