Russian troops threaten to open fire in tense stand-off

This is the moment tensions threatened to boil over in Crimea as Russian troops fired waing shots at a group of unarmed Ukrainian soldiers.

Remarkable footage captured the tense stand-off today between the two sides at the Belbek air base, previously manned by Ukrainians.

It shows Russian soldiers threatening to shoot the 300 Ukrainian soldiers who were marching in protest and demanding their jobs back.

About a dozen Russian soldiers at the base waed the Ukrainians not to approach.

They fired several waing shots into the air and said they would shoot the Ukrainians if they continued to march toward them.

One Russian soldier says: ‘I want your officer here. We"ll be shooting your legs.

A Ukrainian soldier responds: ‘You will pay for this. You"ll be responsible."

Another adds: ‘America stands with us."

The Russian soldier then replies: ‘Commander, calm down your crowd."

Vladmir Putin later said sending troops into Ukraine was a ‘last resort", but insisted he reserved the right to take ‘all measures" to protect the country"s Russian-speaking population.

He also denounced the removal of president Viktor Yanukovych as an ‘unconstitutional coup d"etat" and said the country"s current interim administration was not legitimate.

Tensions have been running high in the Black Sea peninsula since Russian troops tightened their grip over the weekend on the Crimean peninsula, where Moscow"s Black Sea Fleet is based.