Ukraine: 'Snipers on the bank' at Belbek air base
4 March 2014 Last updated at 16:47 GMT
Crimea has become the major focus of post-uprising Ukraine, as troops in what appear to be Russian uniforms surround Ukrainian military bases.
In a sign of the extreme fragility, a Russian soldier fired three volleys of shots over the heads of Ukrainian airmen who marched unarmed towards their aircraft at Belbek air base near Sevastopol.
After a stand-off in which the two commanders shouted at each other and Russian soldiers levelled rifles and rocket-propelled grenade launchers at the Ukrainians, the incident was defused and the Ukrainians eventually dispersed.