"Sevastopol is a Russian town," yelled retiree Zinaida Lazereva, while a group of elderly ladies sang Soviet war songs nearby her on the city's main square.

"Here we speak Russian, we have a Russian mentality and we want to be in Russia," she told AFP, as military ships could be seen moored up in the bay below.

Perched on the southwestern tip of Ukraine's Crimea peninsula, Sevastopol has been the home of the Russian navy's Black Sea fleet for some 250 years and a bastion of pro-Kremlin sentiment since the collapse of the Soviet Union saw it cut off from Moscow.

Now the town is a key chess piece in the spiralling tensions over the Russian-speaking Crimea, which has descended further and further into disarray since the ouster of Kremlin-backed president Viktor Yanukovych following an explosion of deadly protests.

Armed men that Kiev believes are backed by Moscow have seized key government buildings in the region and surrounded Ukrainian military bases, and Russia's parliament on Saturday approved the deployment of troops into the country.

On Sunday, just one day after he was appointed by Ukraine's new interim president, the country's navy chief announced from Sevastopol that he was switching his allegiance to the region's pro-Moscow government, which Kiev has declared illegal.

While the West denounces what it sees as Moscow's creeping annexation of Crimea -- which was controlled by Russia until it was handed to the Ukrainian Soviet republic in 1954 -- as inexcusable aggression, in Sevastopol many seem to welcome any Russian intervention.

"Putin is not seizing anything," said pensioner Lidia Alexandrovna, the colours of the Russian tricolour pinned to her jacket.

"The Russians are not taking over, they are coming here to save us."

Around the town there is little sign that Sevastopol is at the centre of an international storm and armed troops aren't visible on the streets.

The atmosphere is calm as families saunter along and pensioners stand in groups and gossip. Russian flags far outnumber Ukrainian ones on buildings around town.

- Burn our houses, hang us -

But fear is rampant as people struggle to digest the bloody upheaval that left almost a hundred dead in Kiev and saw Yanukovych's government replaced by a pro-EU administration backed mainly by the country's Ukrainian-speaking nationalist regions to the west.

Fuelled in part by widely-watched Russian television broadcasts that routinely described protesters in Kiev as fascists -- many see the new government as a direct threat to themselves and their families.

"These terrorists want to come and destroy our monuments and the history of our struggle against fascism," said former submariner Vasily Gradsky.

"They want to come and burn our houses and have said they'll hang people for talking in Russian," he said.

Concern that their language and heritage may come under seige has apparently led some to start taking action themselves.

Standing in freshly ironed military fatigues, clothing boutique owner Stanislav Nagorny says that some 5,000 people have signed up, over the past week, for a self-defence group he represents.

"When you see that Nazism has appeared in the west of Ukraine and arrived now in Kiev, you can't stay at home," he says, standing outside a teacher training college that has become the group's headquarters.

"I'm just a man, a simple citizen. No one is paying me to be here."

Nagorny's group is not the only one claiming that the town's Russian-speaking population need protection.

In a central square dozens of cossacks from the nearby Russian region of Kuban lined up in rough formation, mismatching uniforms and traditional hats.

"Wherever our Russian brothers are in need of help we will come to help protect them," commander Sergey Savotin said.

"We came a few days ago and we will stay as long as we have to to work with the police and keep order," he said, as some of the cossacks shook hands and laughed with local law enforcement officials.

While many say that they want to see Crimea become part of Russia, not everyone thinks that things need go that far.

"I don't think it will end up with us joining Russia but it could lead to greater autonomy," says Dina Toporskaya, a windsurfing instructor in her twenties.

"It is just that there has been so much change and people are scared now."