Odessa residents prepare to defend city

STORY: Occasionally bursting into song, citizens from all walks of life from photographers to choreographers and comedians helped pack the bags, an effort that has been underway since February 27, organisers said.

Organisers estimate that 400,000 bags of sand have been shifted so far.

The mayor of Odessa has warned Russian forces could soon surround his southern Ukrainian port city on three fronts.

Mayor Gennadiy Trukhanov suggested Russian forces would seek to advance from territories they have occupied in Ukraine’s Mykolaiv region towards Moldova's separatist-controlled Transdniestria region, where Russian troops are based.

Such a move could cut Odessa off from the rest of Ukraine.