A bunch of Serbian war veterans identifying themselves as Chetniks have joined pro-Russian troops occupying Ukraine's Crimea region.

Wearing military uniforms a small unit of about five people claiming to be members of the historic Serbian nationalist guerrilla force, were seen checking cars at a roadblocks in Crimea.

"We came simply to support the referendum," the unit's commander Bratislav Zivkovic told Vice.

"Our main goal is to prevent war and bloodshed and to prevent this area from falling under the lies of America and the European Union."

Chetniks first emerged at the beginning of last century as a nationalist and monarchist paramilitary group that fought in the Balkan wars and World War I.

During World War II the name Chetnik came to identify a disparate number of militia groups that fought against Nazi Germans, Croats, rival communist partisan groups and Muslims, with the broad aim to secure an ethnically-pure Greater Serbia.

The group resurfaced as ethnic violence erupted during the Yugoslavian wars in the 1990s. Zivkovic claimed he fought in Kosovo, Bosnia and Croatia.

"Russians always came to volunteer in Serbian wars when we faced hardships and now we came here to help them," Zivkovic said.

At a roadblock between the Crimean capital of Simferopol and the port town of Sevastopol another militant sporting the Serbian nationalistic acronym for "Only Unity Saves the Serbs", told The BBC he was there to help his "Russian Orthodox brothers".

"We are the same and it's normal that I'm here," he said.

Tensions in Crimea, the only region of Ukraine populated by a majority of ethnic Russians, have been rising after rebel protesters ousted kremlin-backed president Viktor Yanukovich.

The region has been taken over by armed troops believed to be Russian soldiers. Alongside them self-defence groups and Cossacks have been patrolling key locations in the peninsula.

The Crimean parliament has called a referendum for the region to secede from Ukraine and join Russia instead. The Ukrainian interim government has called the referendum illegal, as have the US and EU.

Meanwhile a leader of Crimea Muslim Tatars said that occupying Russian forces will face bloody reprisals if the referendum is successful.