With fierce fighting in cities along the southern coast of Ukraine, the key city of Odesa is preparing defensive forces.
The President of Ukraine has warned that Russia plans to bomb the city. Russian landing craft have been seen offshore and several planes are believed to have been shot down.
Odesa is seen as an important target, both strategically and symbolically. The BBC has obtained footage of volunteers preparing to defend the city, just 50 kilometers (30 miles) from the border with Moldova.
